CN101048907A - Electrode support for fuel cell - Google Patents

Abstract

An electrode support for fuel cell comprised of a porous body having a Ni phase of Ni or NiO and an inorganic aggregate phase, characterized in that at least one metal (M) for oxidation-reduction swelling inhibition selected from the group consisting of Fe, Co and Mn is solid dissolved in the Ni phase or is unevenly distributed in a grain boundary between the Ni phase and the inorganic aggregate phase. This electrode support minimizes a volume swelling/shrinkage change even in an environment of alternate exposure to a reducing atmosphere and an oxidizing atmosphere. The fuel cell comprising this electrode support and, superimposed thereon, afuel electrode, a solid electrolyte layer and an oxygen electrode realizes effective prevention of cracking, detachment, etc. by, for example, swelling encountered when a reduction/oxidation cycle is repeated by power generation and halting of power generation, thereby strikingly excelling in long-term reliability.

Description

Electrode support for fuel cell

Technical field

The present invention relates to a kind of electrode support for fuel cell, specifically, relate to a kind ofly in solid electrolyte fuel cell, be used to support the electrode support of the duplexer of above-mentioned electrode structure or solid electrolyte layer and oxygen utmost point layer with the electrode structure that between the fuel electrodes and the oxygen utmost point, accompanies solid electrolyte layer.

Background technology

As the energy of a new generation, proposed the battery pack of fuel cell is accommodated in the multiple scheme of the fuel cell assembly in the accommodating container in recent years.

Figure 11 represents the battery pack (stacks of cells) of existing solid electrolyte fuel cell, constituting of this stacks of cells: make a plurality of fuel cells 1 arrange set, make the collector component of being made up of metal felt (felt) 5 between a fuel cell 1a and other a fuel cell 1b of adjacency, the fuel electrodes 7 of a fuel cell 1a electrically connects with the oxygen utmost point (air pole) of another fuel cell 1b 11.

Fuel cell 1 (1a, 1b) constitutes: on the outer peripheral face of the fuel electrodes 7 that is made of cermet cylindraceous (inner is fuel gas channels), the oxygen utmost point 11 that sets gradually solid electrolyte 9 and constitute by conductivity ceramics, on not by the surface of the fuel electrodes 7 of solid electrolyte 9 and 11 coverings of the oxygen utmost point, be provided with internal connector 13.As shown in figure 11, this internal connector 13 is not connected with the oxygen utmost point 11 as can be known, and electrically connects with fuel electrodes 7.

Internal connector 13 is formed by the conductivity pottery, this conductivity ceramics is not perishable in oxygen-containing gass such as fuel gas and air, but, this conductivity pottery must have fine and close structure, positively the fuel gas of fuel electrodes 7 inside of flowing through and the oxygen-containing gas in the oxygen utmost point 11 outsides of flowing through are interdicted.

In addition, be set at the collector component 5 between fuel cell 1a, the 1b that adjoins each other, electrically connect through the fuel electrodes 7 of an internal connector 13 and a fuel cell 1a, and with the oxygen utmost point 11 electric connections of other a fuel cell 1b, thus, the fuel cell series of adjacency connects.

The stacks of cells that fuel cell will have said structure is accommodated in the accommodating container, uses with the form of assembly, for example, and at the internal circulation fuel gas (hydrogen) of fuel electrodes 7, at oxygen utmost point ventilating air (oxygen), generating about 750～1000 ℃.

In above-mentioned fuel cell, fuel electrodes 7 is by containing Ni and the Y that is called as stable yittrium oxide zirconium (YSZ) generally speaking ₂O ₃ZrO ₂Form, solid electrolyte 9 is by containing Y ₂O ₃ZrO ₂(YSZ) form, the oxygen utmost point 11 is made of the perovskite composite oxide of lanthanum manganese class.

As the method for this manufacturing fuel cell, be known that the co-sintering method, form by the while calcinating fuel utmost point 7 and solid electrolyte 9.This co-sintering method technology is very simple, and manufacturing process is few, helps improving the rate of finished products when making and reducing production costs.

Yet, form the Y that contains of solid electrolyte 9 ₂O ₃ZrO ₂, its thermal coefficient of expansion is 10.8 * 10 ^-6/ ℃ about, relative therewith, the thermal coefficient of expansion of the fuel electrodes 7 of support solids electrolyte 9 is 16.3 * 10 ^-6/ ℃ about; And compare with YSZ, have very large Ni content.Therefore, when carrying out above-mentioned when calcining time, its thermal expansion difference of fuel electrodes 7 of solid electrolyte 9 and supporting becomes big, can be created in problems such as occurring slight crack on the fuel electrodes 7 or cause that solid electrolyte 9 is peeled off.

As the fuel cell that has solved the problems referred to above, be known that on by the supporting substrates of forming, form the fuel cell (referring to Patent Document 1) of fuel electrode, solid electrolyte, oxidizing electrode layer.

According to above-mentioned fuel cell, because can make the thermal coefficient of expansion of the thermal coefficient of expansion of supporting substrates, so slight crack occurs or solid electrolyte is peeled off from fuel electrodes in fuel electrodes can suppress to calcine simultaneously the time near solid electrolyte.

Patent documentation 1: the spy opens the 2004-146334 communique

As described above,, in patent documentation 1, proposed multiple schemes of countermeasures, but in fuel cell, except thermal expansion, also had the expansion issues that causes because of redox cycle at the fault that causes because of thermal expansion.

Promptly, when generating electricity, because the supply of fuel gas (hydrogen), fuel battery inside is exposed in the reducing atmosphere, but when generation outage, consider fail safe and economy, be cut off, make inside battery become oxidizing atmosphere from reducing atmosphere to the inside battery supplied fuel gas that is under the condition of high temperature.Yet, in fuel cell,, use electrode support generally speaking for the intensity that keeps stipulating, on this electrode support, form electrode structure, and carry out current collection through electrode support.For example the battery of Figure 11 has fuel electrodes 7 becomes electrode support, is the structure that the solid electrolyte 9 and the oxygen utmost point 11 are set on the fuel electrodes 7 at this electrode support.Such electrode support generally occupies the major part of battery volume.Much less, be formed with on electrode support in the fuel cell of stepped construction of fuel electrodes, solid electrolyte and the oxygen utmost point, electrode support accounts for the major part of battery volume too.Therefore, the such stability of electrode support in atmosphere changes is very important.

But above-mentioned electrode support contains and is useful on the metal of paying conductivity, generally adopts Ni as such metal.Because Ni has the function that generates the modifying catalyst of fuel gas (hydrogen) from natural gas, can realize effective utilization of fuel, in addition, also contain Ni in the fuel electrodes, when on electrode support, forming fuel electrodes, can prevent the fault that the Elements Diffusion between the fuel electrodes and electrode support at high temperature causes effectively., oxidation takes place in metals such as Ni in the oxidizing atmosphere that generation outage etc. causes, and the volume of electrode support produces expansion thereupon.In addition, because oxidized metal can obtain reduction in reducing atmosphere, the electrode support after the expansion produces and shrinks.Therefore, make oxidizing atmosphere change to reducing atmosphere, the volume that may be thought of as electrode support theoretically becomes former state, but in fact can not recover former state, but become the state that more or less expands, so, owing to change atmosphere (promptly generating electricity repeatedly and generation outage) so repeatedly, the volume of electrode support increases gradually, because the expansion of electrode support, can produce solid electrolyte of being formed on the electrode support etc. and slight crack occur, perhaps solid electrolyte is peeled off, and problems such as slight crack appear in electrode support self, and these problems become the mortality reason that battery damages.Actual conditions are, up to now, do not change the mechanism of the volumetric expansion that causes and any correlative study of carrying out that how to prevent this problem at electrode support because of atmosphere as yet.

Summary of the invention

Therefore, the objective of the invention is to, the electrode support that provides a kind of fuel cell to use even be in the environment that reducing atmosphere and oxidizing atmosphere changes mutually, also can suppress volumetric expansion.

Other purpose of the present invention is, a kind of fuel cell is provided, and has above-mentioned electrode support, and its long-term reliability is improved.

According to the present invention, a kind of electrode support for fuel cell is provided, it is characterized in that, using in the electrode support with the fuel electrode that inorganic aggregate porous body mutually forms mutually by having the Ni that constitutes by Ni or NiO,

The redox of selecting from the metal group that Fe, Co, Mn constitute is expanded and is suppressed at least a with metal M, be solid-solubilized in described Ni mutually in, perhaps be partially Ni mutually with inorganic aggregate crystal boundary mutually in.

In electrode support of the present invention, be preferably:

(1) described inorganic aggregate is the rare earth element oxide;

(2) described inorganic aggregate is Y ₂O ₃

(3) described redox expansion inhibition is Mn with metal M, with NiMn ₂O ₄, MnYO ₃Or Y ₂NiO ₆Form separate out in crystal boundary;

(4) described redox expansion inhibition is Fe with metal M, with NiFe ₂O ₄Or FeYO ₃Form separate out in crystal boundary;

(5) described Fe is in the crystal boundary partially;

(6) described redox is expanded, and to suppress with metal M be Co, solid solution in Ni mutually in.

In addition, according to the present invention, can provide a kind of being configured on a face of above-mentioned electrode support, to stack gradually the solid electrolyte fuel cell of fuel electrodes, solid electrolyte and the oxygen utmost point.

Moreover, according to the present invention, can provide a kind of stacks of cells that above-mentioned fuel cell series is formed, and this stacks of cells is received into the fuel cell assembly that forms in the accommodating container.

Electrode support for fuel cell of the present invention, form with inorganic aggregate porous body mutually mutually by having Ni, but important being characterised in that, above-named redox is expanded and is suppressed to use metal M, perhaps solid solution in Ni mutually in, perhaps be Ni partially mutually and in the inorganic aggregate crystal boundary mutually, owing to there is such metal M, can suppress the reduction-oxidation volumetric expansion that (changing reducing atmosphere and oxidizing atmosphere repeatedly) cause that circulates effectively.

That is, Ni this electrode support in opposite directions pays electric conductivity and as the function of modifying catalyst, and inorganic aggregate is made of the inorganic material that has stability characteristic (quality) for oxidizing atmosphere and reducing atmosphere, forms the basic framework of supporting mass.Has a Ni when being exposed in reducing atmosphere and the oxidizing atmosphere alternately with inorganic aggregate supporting mass (porous body) mutually mutually when oxidation (reduce repeatedly) when such, Ni mutually in, reduce repeatedly alternately and oxidation, the words Ni of oxidation becomes oxide, respective volume expands, therefore, and theoretically, shrink producing after this oxide reduction, should return to existing volume.Yet, as previously mentioned, even in fact can not return to existing volume after the reduction yet, reduce repeatedly, under the effect of oxidation, electrode support expands gradually.The circulate intumescent mechanism of caused supporting mass of such a reduction-oxidation do not obtain correct illustrating, but the present inventor person etc. has been made following deduction.

When Ni produce to expand because of oxidation in mutually, the inorganic aggregate that is present in around it is pushed to the outside mutually, expands so electrode support produces.Secondly, be in the reducing atmosphere when Ni takes place to reduce in mutually, NiO becomes Ni and produces contraction., constitute the inorganic aggregate (for example rare earth element oxide etc.) of electrode support, have stability for oxidation, reduction, bad with the wetability of metallic nickel (perhaps its oxide).Therefore, under the state that oxidation causes expanding, even inorganic aggregate mutually with dilated Ni good bond mutually, when reduction causes that Ni shrinks mutually, the after-contraction (inorganic aggregate does not shrink with the contraction of Ni phase mutually) that is separated of Ni and the inorganic aggregate of a part, its result is because of the volume of the dilated electrode support of oxidation, can be because of reduction does not restore to the original state, becoming is slightly larger than the preceding volume of oxidation.

The present invention can play the expansion that inhibition causes because of such reduction-oxidation circulation by adding specific metal M, and for its mechanism that suppresses, the present inventor person etc. make following deduction.

At first, expand in above-mentioned redox and to suppress with in the metal M, Mn and Fe are for Ni and inorganic aggregate (Y for example ₂O ₃) having reactivity, when calcining in the electrode support manufacture process, its reactant or precipitate into Ni mutually and in the inorganic aggregate crystal boundary mutually is perhaps with non-reactant but be crystal boundary partially with the form that is rich in.Its result, Ni is improved with inorganic aggregate wetability mutually mutually, when Ni reduces contraction mutually, the inorganic aggregate Ni that accompanying shrinks mutually, the contraction that produces when thereby the expansion that produces when making oxidation is reduced is offset, and has therefore avoided the swelling of the electrode support that causes because of the reduction-oxidation circulation effectively.In addition, these metal M are polyvalent metals, and trace gets final product solid solution in the Ni phase, but the speed of growth of Ni oxide significantly improves at this moment.So when being in oxidizing atmosphere, the Ni oxide is towards the pore growth inside of the electrode support body weight of porous body.Because oxygen is fed to pore inside easily.So when Ni oxide during towards the inner growth fast of pore, be positioned at inorganic aggregate around it by Ni phase tractive, its oxidation expansion that produces in oxidizing atmosphere as a result is minimum, sometimes even shrink.Therefore, though the metal M solid solution in Ni mutually in and cause that the speed of growth of Ni oxide accelerates, also can suppress the expansion that causes because of reduction-oxidation circulation effectively.

In addition, expand inhibition with in the metal M in redox, because the full ratio solid solution of Co meeting is in the Ni phase, so can not produce the material that reacts with inorganic aggregate, solid solution the Ni of Co be improved mutually with inorganic aggregate wetability mutually, its result is same as described above, when the reduction contraction of Ni phase, the contraction that inorganic aggregate accompanies, thus the expansion of the electrode support that causes because of reduction-oxidation circulation avoided effectively.

In addition, in the present invention, the separating out of the reactant of Ni or inorganic aggregate and metal M, crystal boundary partially and solid solution in the existence of the metal M of Ni, can pass through selected area electron diffraction analysis (SAED) and X-ray energy spectrum analysis (EDS), secondary ion mass spectroscopy analysis (SIMS) that x-ray powder diffraction instrument (XRD) or electro probe-X-ray microanalysis (EPMA), particularly transmission electron microscope (TEM) carry out confirms.

So, the expansion that electrode support of the present invention causes because of reduction-oxidation circulation obtains reducing, and as described later shown in the embodiment, the absolute value of linear expansivity of reduction-oxidation circulation time that carries out 3 times repeatedly is below 0.2%.

The present invention electrode support, being used as the fuel cell that is formed with fuel electrodes layer, solid electrolyte, oxygen utmost point layer on electrode support is successively used, even under the situation that starts repeatedly and stop, also can effectively suppress to occur in fuel electrodes and the solid electrolyte slight crack and problem such as peel off, for example: in the actual use of the general home-use fuel cell of frequent switch, can improve its long-term reliability.

Description of drawings

Fig. 1 is the cross-sectional view that expression possesses the fuel cell of electrode support of the present invention.

The cross-sectional view of Fig. 2 battery supply group that to be expression formed by the fuel cell of Fig. 1.

Fig. 3 is the curve chart of the electrode support of test portion No.1～4 of preparation in the expression experimental example 1 through the linear expansivity after the reduction-oxidation cyclic test.

Fig. 4 is the element reflection of expression with the electrode support (example of the present invention) of the test portion No.3 of preparation in the experimental example 1 of TEM-EDS mensuration.

Fig. 5 is the bright-field image of expression with the electrode support (example of the present invention) of the test portion No.3 of preparation in the experimental example 1 of TEM mensuration.

Fig. 6 is the elementary analysis spectrum of expression with the grain circle phase of the electrode support (example of the present invention) of the test portion No.3 of preparation in the experimental example 1 of TEM-EDS mensuration.

Fig. 7 is the selected area electron diffraction analysis result of expression with the grain circle phase of the electrode support (example of the present invention) of the test portion No.3 of preparation in the experimental example 1 of TEM mensuration.

Fig. 8 is the curve chart of the electrode support of test portion No.5～8 of preparation in the expression experimental example 2 through the linear expansivity after the reduction-oxidation cyclic test.

Fig. 9 is the bright-field image of expression with the electrode support (example of the present invention) of the test portion No.7 of preparation in the experimental example 2 of TEM mensuration.

Figure 10 is the results of elemental analyses of expression with the grain circle portion of the electrode support (example of the present invention) of the test portion No.7 of preparation in the experimental example 2 of TEM-EDS mensuration.

Figure 11 is the cross-sectional view of the stacks of cells that is made of existing fuel cell of expression.

Embodiment

Below, the present invention is described in detail for the concrete example shown in reference to the accompanying drawings.

Fig. 1 is the sectional view that expression possesses the fuel cell of electrode support of the present invention, and in Fig. 1, the fuel cell of representing as all usefulness 30 is the hollow tabular, and the cross section is a flat, possesses the electrode support 31 of elongated plate-like as a whole.In the inside of electrode support 31, connect length direction and be formed with fuel gas channel 31a with proper spacing, fuel cell 30 has the structure that is provided with various members on this electrode support 31.As shown in Figure 2, generally speaking, with will be a plurality of by collector component 40 30 series connection of such fuel cells form stacks of cells, the mode that again stacks of cells is encased in formation fuel cell assembly in the accommodating container of regulation is used fuel cell 30.

From shape shown in Figure 1 as can be known electrode support 31 constitute by the arcus part B at par A and A two ends, par.The two sides of par A forms roughly and is parallel to each other, fuel electrodes layer 32 is made as the face of a side that covers par A and the arcus part B of both sides, moreover, be laminated with dense solid electrolyte layer 33 in the mode that covers this fuel electrodes layer 32, on this solid electrolyte layer 33, relative with fuel electrodes layer 32, stacked aerobic utmost point layer 34 on the surface of par A.

In addition, on another surface of the par A that does not have stacked fuel electrodes layer 32 and solid electrolyte layer 33, be formed with internal connector 35.Express as Fig. 1, fuel electrodes layer 32 and solid electrolyte layer 33 constitute till the both sides that extend to internal connector 35, and the surface of electrode support 31 is not exposed to the outside.

In the cell of fuel cell of above-mentioned structure, the utmost point work generating that acts as a fuel of the part relative of fuel electrodes layer 32 with oxygen utmost point layer 34.Promptly, the flow through outside of oxygen utmost point layer 34 of the oxygen-containing gas of air etc., and fuel gas (hydrogen) the gas passage 31a in the electrode support 31 that flows through, be heated to the working temperature of regulation, thereby in the electrode reaction of the oxygen utmost point layer 34 following formula of generation (1), in addition, on the part of the fuel electrodes that becomes fuel electrodes layer 32, the electrode reaction of following formula (2) for example takes place, thereby generates electricity.

The oxygen utmost point: 1/2O ₂+ 2e ^-→ O ^2-(solid electrolyte) ... (1)

Fuel electrodes: O ^2-(solid electrolyte)+H ₂→ H ₂O+2e ^-... (2)

The electric current that above-mentioned generating produces is through being installed in internal connector 35 current collections on the electrode support 31.Promptly, by a plurality of fuel cells 30 series connection formation shown in Figure 2 stacks of cells of collector component 40 with above-mentioned structure, the battery assembly that acts as a fuel after again this stacks of cells being received in the accommodating container of regulation uses, by making fuel gas (hydrogen) and oxygen-containing gas flow to the position of regulation, can play the effect of battery.

(electrode support 31)

In fuel cell 30 with above-mentioned structure, electrode support 31 need have the gas-premeable that is used to make till fuel gas penetrates into fuel electrodes layer 32, in addition, in order to carry out current collection through internal connector 35, also require to have conductivity, moreover, also require by described later simultaneously when fuel cell 30 is made in calcining phenomenon such as the slight crack that causes because of thermal expansion difference can not occur or peel off.In order to satisfy these requirements, electrode support 31 is the conductivity porous body, and the inorganic aggregate that has the phase (Ni phase) of metallic nickel (Ni) or its oxide (NiO) and form basic framework mutually.

Promptly, Ni is used for paying conductivity to electrode support 31 mutually, forming by nickel oxide (NiO) in the situation or oxidizing atmosphere of Ni phase, nickel oxide (NiO) forms the Ni phase, but become reducing atmosphere during owing to generate electricity, form the Ni phase by nickel oxide (NiO), demonstrate good electrical conductivity.In addition, because such Ni also has the function of modifying catalyst mutually, even remaining in the fuel gas (hydrogen) have a natural gas (CH ₄), can be hydrogen also, thereby reach the purpose of effectively utilizing fuel such gas upgrading.Moreover, in fuel electrodes layer 32 described later, include Ni generally speaking, but by Ni is included in the electrode support 31 mutually, the Elements Diffusion in the time of can avoiding calcining effectively or during generating between electrode support 31 and the fuel electrodes layer 32.

In addition, inorganic aggregate is formed by the inorganic oxide that has stability characteristic (quality) for oxidizing atmosphere and reducing atmosphere, forms the basic framework of electrode support 31, pays the intensity of regulation.As such inorganic oxide,, and prevent diffusion, the suitable rare earth element oxide that uses to solid electrolyte layer 33 etc. particularly for the thermal coefficient of expansion that makes electrode support 31 is similar to solid electrolyte layer 33.As the rare earth element oxide, can exemplify out Y ₂O ₃, Lu ₂O ₃, Yb ₂O ₃, Tm ₂O ₃, Er ₂O ₃, Ho ₂O ₃, Dy ₂O ₃, Gd ₂O ₃, Sm ₂O ₃, Pr ₂O ₃Deng, but consider cheap problem, be preferably Y ₂O ₃

In order to keep the favorable conductive rate, and guarantee to have the thermal coefficient of expansion approximate with the solid electrolyte material that forms solid electrolyte layer 33, convert by oxide, above-mentioned Ni composition and inorganic aggregate, with the Ni composition: the volume ratio of inorganic aggregate=35: 65 to 65: 35 is contained in the electrode support 31.

In addition, because electrode support 31 need have the fuel gas permeability, the open pore rate is more than 30% usually, is preferably 35～50% scope, and its conductance is more than the 300S/cm, to be preferably more than the 440S/cm.

Moreover the length of the par A of electrode support 31 is generally 15～35mm, and the length of arcus part B (length of arc) is about 3～8mm, and the thickness of electrode support 31 (interval on the two sides of par A) is preferably about 2.5～5mm.

In electrode support 31 of the present invention, though have above-mentioned various characteristics, but the particularly important is the redox expansion of from the metal group that constitutes from Fe, Co, Mn, selecting and suppress to use at least a of metal M, be solid-solubilized in described Ni mutually in, perhaps be partially Ni mutually with inorganic aggregate crystal boundary mutually in.Form both can be the form of the reactant of Ni or inorganic aggregate partially, also can be the enrichment in crystal boundary portion.Promptly, when electrode support 31 by above-mentioned Ni mutually with situation that porous body that inorganic aggregate constitutes mutually forms under, follow the reduction-oxidation circulation of generating and generation outage to cause that the volume of electrode support 31 expands, cause producing slight cracks and fuel electrodes layer 32 and problem such as peel off, thereby make the long-term reliability of fuel cell obtain damaging at solid electrolyte layer 33.Yet, be present in Ni mutually or Ni mutually and in the no aggregate crystal boundary mutually by above-mentioned redox being expanded suppress with metal M, can prevent to cause the volumetric expansion that the reduction-oxidation of various faults circulates and causes effectively.

That is, redox expand to suppress to have reactivity with Mn and Fe in the metal M for Ni and inorganic aggregate, when in the electrode support manufacture process, calcining, and can generation and the reactant of Ni and inorganic aggregate.As such reactant, for example can enumerate the reactant NiMn of Mn and Ni ₂O ₄Mn and rare earth element oxide (Y ₂O ₃) reactant MnYO ₃And the reactant Y of Mn and Ni and rare earth element oxide ₂NiMnO ₆Deng.In addition, can also enumerate the reactant NiFe of Fe and Ni ₂O ₄Fe and rare earth element oxide (Y ₂O ₃) reactant FeYO ₃Deng.The reactant of such metal M and Ni or inorganic aggregate is mainly separated out at Ni mutually and in the inorganic aggregate crystal boundary mutually, so, is separating out under the effect of the reactant of crystal boundary, and the Ni phase is improved with inorganic aggregate wetability mutually.In addition,, shown in the experimental example 2, exist partially as described later, also can improve Ni phase and inorganic aggregate wetability mutually with the form metal M generation of enrichment in crystal boundary even be not reactant.Its result, when the reduction that produces the Ni phase is shunk, the accompanying reduction of Ni phase of inorganic aggregate is shunk and is shunk, and the contraction the when expansion that the oxidation of Ni phase is caused is reduced is offset, thereby avoids effectively because of the circulate expansion of the electrode support 31 that causes of reduction-oxidation.

Moreover, when these polyvalent metal solid solutions in Ni mutually in the time, as previously mentioned, the speed of growth of Ni oxide significantly improves.That is, in the oxidizing atmosphere when generation outage, the Ni oxide is towards the pore growth inside of electrode support (porous body) 31, be positioned at its inorganic aggregate phase on every side, the Ni of oxidized growth pulls to inside mutually, and its oxidation is as a result expanded minimum, according to circumstances also can produce contraction sometimes.Therefore, in the aforesaid inhibition of the oxidation expansion being carried out by the solid solution of other metal M, also can reduce the expansion that the reduction-oxidation circulation causes effectively.

Expand to suppress with in the metal M in redox and since Co full the ratio solid solution, can avoid effectively so improve in the impurity solid solution under the effect of wetability in the Ni phase because of the circulate expansion of the electrode support 31 that causes of reduction-oxidation.

In addition, in the above description, to use Y ₂O ₃As inorganic aggregate is that example is illustrated, but with other rare earth element oxide as under the situation of inorganic aggregate, can obtain same result.

In the present invention, with rare earth element oxide, particularly Y ₂O ₃As inorganic aggregate, moreover, when redox expansion inhibition is Mn, Fe or Co with metal M, can reduce the expansion that causes because of the reduction-oxidation circulation most effectively.

In addition, in the scope of not damaging above-mentioned characteristic, in above-mentioned electrode support 31, also can contain Ni (perhaps NiO), inorganic aggregate and redox expansion and suppress with the composition beyond the metal M.

In addition, at Ni mutually and under the state that inorganic aggregate wetability mutually is improved, during the initial stage reduction, electrode support 31 (being commonly referred to as reduction swellability) can produce expansion.Its reason is still indeterminate, but may cause because the reduction of NiO causes Ni to separate out.Such reduction swellability can be by making Mg, particularly the MgO solid solution in Ni mutually in and effectively suppressed, this point has obtained affirmation in experiment.Such Mg amount is preferably when adding up to (Mg+Ni) with Ni, is in the scope of 0.1 to 20 mole of %.

(fuel electrode layer 32)

In the present invention, fuel electrode layer 32 takes place by the electrode reaction in the described formula (2), and himself is formed by the conductive metal pottery of disclosed porous matter.The ZrO that rare earth element for example, is arranged by solid solution ₂Form with Ni and/or NiO.The ZrO that this rare earth element is arranged as solid solution ₂(stable yittrium oxide zirconium) also can use and be used to form solid electrolyte layer 33 identical materials described later.

The content of the stable yittrium oxide zirconium in the fuel electrodes layer 32 is preferably the scope of 35～65 volume %, and the content of Ni or NiO is preferably 65～35 volume % in addition.Moreover the open pore rate of this fuel electrodes layer 32 is more than 15%, is preferably 20～40% scope, and its thickness is preferably 1～30 μ m.For example, the thickness of fuel electrodes layer 32 is crossed when thin, and performance might reduce, and when too thick, might cause problem such as peel off because of the thermal expansion difference between solid electrolyte layer 33 and the fuel electrodes layer 32.

In addition, in example shown in Figure 1, this fuel electrodes layer 32 extends to till the both sides of internal connector 35, but because as long as this fuel electrodes layer 32 is present on the position relative with the oxygen utmost point 34 and is formed with the words of fuel electrodes, thus only on the par A that is provided with the oxygen utmost point 34 1 sides formation fuel electrodes layer 32 also can.Moreover, also can be around the full week formation fuel electrodes layer 32 of supporting substrates 31.In the present invention, in order to improve the bond strength of solid electrolyte layer 33 and supporting substrates 31, be preferably whole solid electrolyte layer 33 is formed on the fuel electrodes layer 32.

(solid electrolyte layer 33)

Be located at the solid electrolyte layer 33 on this fuel electrodes layer 32, general by solid solution 3～15 moles of % rare earth element be called as ZrO ₂The compactness pottery of (stable yittrium oxide zirconium) forms.As rare earth element, can exemplify out Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu etc., when viewpoint, be preferably Y, Yb from cheapness.

Form the stable yittrium oxide zircon ceramic of this solid electrolyte layer 33, from preventing the viewpoint of gas permeation, its relative density (Archimedes's method) is more than 93%, is preferably the compact substance more than 95%, and its thickness is preferably 10～100 μ m.As solid electrolyte layer 3, except stable yittrium oxide zirconium, also can constitute by the Ca-Ti ore type constituent of lanthanum manganese class.

(oxygen utmost point layer 34)

Oxygen utmost point layer 34 is by so-called ABO ₃The conductivity ceramics that the perofskite type oxide of type constitutes forms.As such perofskite type oxide, be preferably the transition metal perofskite type oxide, especially on the A side, have the LaMnO of La ₃Type oxide, LaFeO ₃Type oxide, LaCoO ₃A kind of in the type oxide, from have high electrical conductivity under the working temperature about 600～1000 ℃, more excellent is to select LaFeO ₃Type oxide.In addition, in above-mentioned perofskite type oxide, on the A side, except La, also can there be elements such as Sr simultaneously, moreover on the B side, except Fe, can also have Co and Mn simultaneously.

In addition, oxygen utmost point layer 34 must have gas-premeable, and the open pore rate that therefore forms the conductivity ceramics (perofskite type oxide) of oxygen utmost point layer 34 is preferably more than 20%, 30～50% scope that more excellent is.

From the viewpoint of current collection, the thickness of such oxygen utmost point layer 34 is preferably 30～100 μ m.

(internal connector 35)

On the position relative with above-mentioned oxygen utmost point layer 34, on electrode support 31, be provided with internal connector 35, it is made up of conductivity ceramics, but because contact with fuel gas (hydrogen) and oxygen-containing gas, needs it to have reducing resistance and oxidative resistance.Therefore, as such conductivity ceramics, generally use the perofskite type oxide (LaCrO of lanthanum manganese class ₃Type oxide).In addition, in order to prevent that the fuel gas by electrode support 31 inside and the oxygen-containing gas of the outside by electrode support 31 from leaking, such conductivity ceramics must have compactness, for example is preferably the relative density that has more than 93%, and more excellent is to have 95% relative density.

From preventing the viewpoint of gas leakage and resistance, the thickness of such internal connector 35 is preferably 10～200 μ m.That is, when thickness during less than this scope, gas leaks easily; And resistance increases when thickness surpasses this scope, might occur causing the low of current collection function because of current potential descends.

In addition, as shown in Figure 1,, on the both sides of internal connector 35, be tightly locked with the solid electrolyte layer 33 of compactness in order to prevent the leakage of gas, in order to improve sealing, for example also can be with by Y ₂O ₃The knitting layer (not shown) that constitutes is arranged between the two sides and solid electrolyte layer 33 of internal connector 35.

On the outside of internal connector 35 (upper surface), p type semiconductor layer 39 is set preferably.That is, in battery pack (with reference to figure 2), on internal connector 35, be connected with the collector component 40 of conductivity by the fuel cell assembling, but when directly being connected collector component 40 on the internal connector 35, become non-ohmic contact, cause that current potential descends change greatly, causes current collection performance to descend.

, be connected on the internal connector 35 by make collector component 40 through p type semiconductor layer 39, both contacts become ohmic contact, and current potential descends and reduces, and can avoid the low of current collection performance effectively.For example, can be with electric current from the oxygen utmost point layer 34 of the fuel cell 30 of a side, be delivered to expeditiously on the electrode support 31 of fuel electrode 30 of opposite side.As such P type semiconductor, can exemplify out transition calcium metal titanium ore type oxide.

Specifically, can use exactly than the LaCrO that constitutes internal connector 35 ₃The material that the type oxide electrical conductivity is bigger, for example, by the LaMnO that on the B side, has Mn, Fe, Co etc. ₃Type oxide, LaFeO ₃Type oxide, LaCoO ₃The P type semiconductor pottery of at least a composition such as type oxide.The thickness of such p type semiconductor layer 39 is preferably the scope of 30～100 μ m.

In addition, also internal connector 35 can be set directly on the flat A of the electrode support 31 that solid electrolyte layer 33 1 sides are not set, fuel electrodes layer 32 be set on also can be in this section, and on fuel electrodes layer 32, internal connector 35 be set.That is, fuel electrodes layer 32 can be arranged on the full week of electrode support 31, and on this fuel electrodes layer 32, internal connector 35 be set.Internal connector 35 when fuel electrodes layer 32 is arranged on the electrode support 31, is helped being suppressed at generation current potential decline on the interface between electrode support 31 and the internal connector 35.

(manufacturing of electrode support and fuel cell)

Have the electrode support 31 of above-mentioned structure, and the following manufacturing of fuel cell that possesses this electrode support 31.

Mass ratio mixing Ni at first, in accordance with regulations or its oxide powder and Y ₂O ₃Deng inorganic aggregate powder, and comprise described redox and expand and suppress to use the compounds of metal M powder, moreover, be modulated into slurry after organic bond such as acrylic resin or polyvinyl alcohol and isopropyl alcohol or water equal solvent mixed, this slurry is carried out extrusion molding, make electrode support body and function formed body, then it is carried out drying (by this electrode support body and function formed body is calcined, obtaining electrode support 31).

In addition, expand to suppress use compounds of metal M as comprising redox, if can produce described solid solution in Ni mutually or reactant separate out phenomenon in crystal boundary, any compound all can, but preferred usually use oxide (Fe for example ₂O ₃, Mn ₂O ₃, Co ₃O ₄Deng).In addition, make the metal M solid solution in Ni mutually in the time, also can use with the form of the alloy of Ni etc.

Secondly, the fuel electrodes layer is formed with being modulated into slurry after material (Ni or NiO powder and stable yittrium oxide zirconium powder end) and organic bond and the solvent, make the thin slice of fuel electrodes layer usefulness with this slurry.In addition, also can substitute the thin slice of preparation fuel electrodes layer usefulness, the fuel electrodes layer is formed on dispersion of materials is coated on above-mentioned formation to the lotion in the solvent the assigned position of electrode support body and function formed body, make the coating of fuel electrodes layer usefulness after the drying.

Moreover, with the solid electrolyte material powder and the organic bond at stable yittrium oxide zirconium powder end etc., and be modulated into slurry after the solvent, use this slurry to make the solid electrolyte layer thin slice.

The supporting substrates formed body, fuel electrodes layer of preparation as mentioned above with thin slice and solid electrolyte layer thin slice, carried out stacked, dry back formation lit-par-lit structure as shown in Figure 1, under 1000 ℃ of temperature, carry out pre-burning as required again.At this moment, under the situation of the coating that is formed with fuel electrodes layer usefulness on the surface of electrode support body and function formed body, only stacked solid electrolyte layer gets final product with thin slice on electrode support body and function formed body.

Thereafter, with internal connector with material (LaCrO for example ₃The type oxide powder), be modulated into slurry after organic bond and the solvent, make the internal connector thin slice.

Again with this internal connector with sheet lamination to the assigned position of the duplexer of above-mentioned preparation, make calcining and use duplexer.

Then, above-mentioned calcining is removed adhesive treatment with duplexer, in oxygen-containing atmosphere, calcining simultaneously under 1300～1600 ℃ of conditions, on the assigned position of sintered body of preparation, coating contains the aerobic utmost point and forms with material (LaFeO for example by impregnating ₃The type oxide powder) and the lotion of solvent, and as required coating comprises p type semiconductor layer and forms with material (LaFeO for example ₃The type oxide powder) and the lotion of solvent, by at 1000～1300 ℃ of sintering temperatures, can produce and possess the fuel cell 30 of the electrode support 31 of structure as shown in Figure 1.

In addition, when using metallic nickel to form electrode support 31 or fuel electrodes layer 32,, become NiO after Ni is oxidized, be reduced into Ni but can handle (perhaps when generating, placing reducing atmosphere) by reduction owing in oxygen-containing atmosphere, calcine.

In the fuel cell of making like this that possesses electrode support 31 30, can suppress the volumetric expansion of the electrode support 31 that causes because of the reduction-oxidation circulation of following generating (work of fuel cell 30) and generation outage etc. effectively, so can prevent from effectively to cause on solid electrolyte layer 31, producing slight crack because of expansion, or electrode support 31 generation of fault such as peels off, and guarantees long-term stability.

(stacks of cells and fuel cell assembly)

As shown in Figure 2, the formation of stacks of cells is after a plurality of above-mentioned fuel cells 30 are concentrated, make the collector component 40 that constitutes by metal felt and/or metallic plate between fuel cell 30 and another fuel cell 30 of adjacency up and down, both are connected in series.That is, the electrode support 31 of a fuel cell 30 through internal connector 35, p type semiconductor layer 39, collector component 40, is electrically connected on the oxygen utmost point 34 of another fuel cell 30.In addition, as shown in Figure 2, such stacks of cells and row arrangement, the battery pack of adjacency is connected in series by conductive member 42 each other.

The fuel cell of above-mentioned structure is used for stacks of cells with Fig. 2 and is received into fuel cell assembly in the accommodating container.In this accommodating container, be provided with the ingress pipe that will import to from the fuel gas such as hydrogen of outside in the fuel cell 30, and the ingress pipe that is used for oxygen-containing gass such as air are imported to the space outerpace of fuel cell 30, by each fuel cell heating is generated electricity to set point of temperature (for example 600～900 ℃), fuel gas, oxygen-containing gas after being used are discharged into outside the accommodating container.

In addition, the present invention is not limited to aforesaid way, so long as can carry out various changes in the scope that does not change main idea of the present invention.For example, both the shape of electrode support 31 can have been made cylindric, also can be in the fuel cell 30 that possesses electrode support 31, between oxygen utmost point layer 34 and solid electrolyte layer 33, form intermediate layer with suitable conductivity.Moreover, in aforesaid way, be illustrated at the situation that on electrode support 31, has formed fuel electrodes layer 32, but also can self pay the function of fuel electrodes, on the electrode support of the utmost point that acts as a fuel, form solid electrolyte layer and oxygen utmost point layer to electrode support 31.

＜embodiment 1 〉

With following experimental example excellent results of the present invention is described.

(experimental example 1)

Mixing average grain diameter is NiO powder and the Y of 0.5 μ m ₂O ₃Powder (average grain diameter is 0.6～0.9 μ m) makes the NiO after the calcining be scaled 40 volume %, Y with Ni ₂O ₃Be 60 volume %.

Secondly, with Mn ₂O ₃Powder (average grain diameter is 0.7 μ m) divides interpolation, is mixed in the above-mentioned mixed powder 100 quality branch according to the quality shown in the table 1.In addition, in table 1, in the lump the amount (mole %) with respect to the Mn of the total amount of Ni and Mn is represented.

In above-mentioned mixed-powder, the slurry extrusion molding of sneaking into the modulation of hole agent (fibrous cellulose) and organic bond (polyvinyl alcohol) and water (solvent) back is a cuboid, remove the processing of adhesive after being dried, in atmosphere, calcine under 1500 ℃ of conditions, make electrode support (test portion No.1～4).Wherein, in test portion No.1, do not use Mn fully ₂O ₃Powder.

The length that the electrode support for preparing is processed into high 3mm, wide 4mm, length direction is 40mm, is about 10 at oxygen partial pressure ^-19In the reducing atmosphere under the Pa, after the reduction of carrying out under 850 ℃ of conditions 16 hours is handled, in reducing atmosphere, cool off, the length of the length direction before and after the reduction is measured, the linear expansivity of (for the first time) when obtaining reduction by following formula.

Linear expansivity=(length before the length-reduction after the reduction)/(length before the reduction)

Then, in 850 ℃ oxidizing atmosphere, carry out 16 hours oxidation processes after, the linear expansivity of obtaining same as described above.Moreover, carry out three reduction-oxidations circulations in the same way repeatedly, during to reduction and each test portion during oxidation, obtain its linear expansivity from for the third time on.The result is shown in Fig. 3 and table 1.

In addition, for through the above-mentioned electrode support that processes, oxygen partial pressure is about 10 with four-terminal method ^-19Conductance in the reducing atmosphere under the Pa in (850 ℃) is measured.Its result is as shown in table 1.

-Biao 1-

Test portion No.	Mn 2O 3The quality branch	Linear expansivity %						Conductance S/cm
									Reduction for the first time	Oxidation for the first time	Reduction for the second time	Oxidation for the second time	Reduction for the third time	Oxidation for the third time
		*1	0.0	0.06	0.22	0.16	0.30								0.21	0.43	643
2	1.0(1.5)							0.07	0.02	0.08	-0.01	0.07	-0.04	633
		3	1.5(2.3)	0.04	0.09	0.11	0.11								0.11	0.11	624
4	2.0(3.0)							0.08	0.16	0.15	0.20	0.18	0.19	616

^*Represent extraneous test portion of the present invention.

About linear expansivity, expand on the occasion of expression, negative value is represented to shrink.

Mn ₂O ₃Value in the amount in () is mole % (Mn/Mn+Ni).

As can be known from the results of Table 1, by adding Mn ₂O ₃Powder can suppress the expansion that causes because of the reduction-oxidation circulation.In addition, Mn ₂O ₃Amount expands after a little while and becomes negative value (contraction), and amount expands for a long time and becomes big.Moreover, work as Mn ₂O ₃The quantitative change conductance of supporting mass for a long time descends slightly, but conductivity is sufficient.Such Mn amount and the total (Mn+Ni) of Ni are preferably in the scope of 1 to 3 mole of %.

Moreover the tem analysis result that the electrode support of the test portion No.3 of above-mentioned preparation is carried out is shown in Fig. 4～7.

Mn almost evenly is present in Ni/Y as can be seen from Figure 4 ₂O ₃Crystal boundary in.

From Fig. 5～7 as can be known, Mn is as Ni/Y in addition ₂O ₃Crystal boundary distribute mutually, this crystal boundary is Y mutually ₂NiMnO ₆Therefore, can think the change of shape of the Ni the when existence of these crystal boundary phases suppresses that next time, reduction was handled, and suppress the expansion of the electrode support that reduction-oxidation circulation thereafter causes.

(experimental example 2)

Identical with experimental example 1, mix NiO powder and Y ₂O ₃Powder makes the NiO after the calcining be scaled 48 volume %, Y with Ni ₂O ₃Be 52 volume %.With average grain diameter is the Fe of 0.7 μ m ₂O ₃Powder makes it to become the quality branch shown in the table 2 in dividing to these mixed-powder 100 quality, makes electrode support (test portion No.5～9) equally with experimental example 1.In addition, in table 2, merge the Fe amount (mole %) of expression with respect to the total amount of Ni and Fe.

About the electrode support of preparation, same with experimental example 1, the linear expansivity that carries out 3 reduction-oxidations circulation is measured its result such as table 2 and shown in Figure 8.In addition, identical with experimental example 1, the conductance in the reducing atmosphere is measured, its result is as shown in table 2.

-Biao 2-

Test portion No.	Fe 2O 3The quality branch	Linear expansivity %						Conductance S/cm
									Reduction for the first time	Oxidation for the first time	Reduction for the second time	Oxidation for the second time	Reduction for the third time	Oxidation for the third time
		*5	0.0	0.03	0.51	0.33	0.82								0.63	1.08	463
6	0.03 (0.04)							0.06	0.15	0.12	-0.09	0.10	-0.02	727
		7	0.2(0.3)	0.05	-0.02	0.02	-0.13								-0.09	-0.20	745
8	1.0(1.3)							0.08	-0.04	0.01	-0.08	-0.05	-0.11	1024
		9	2.0(2.7)	0.11	0.12	0.09	0.09								0.01	0.12	1220

^*The outer test portion of the expression scope of the invention.

About linear expansivity, expand on the occasion of expression, negative value is represented to shrink.

Fe ₂O ₃Value in the amount in () is mole % (Fe/Fe+Ni).

As can be known from the results of Table 2, by adding Fe ₂O ₃Powder can suppress the expansion that causes because of the reduction-oxidation circulation.In addition, work as Fe ₂O ₃Measure more after a little while, expands to become negative value (contraction), Fe ₂O ₃Amount expands for a long time and becomes big.Moreover work as Fe ₂O ₃Quantitative change for a long time, the conductance of supporting mass also uprises thereupon as can be known.The Fe amount is preferably in the scope of 0.04 to 3 mole of % with the total (Fe+Ni) of Ni.

The result who this supporting mass is analyzed with transmission electron microscope (TEM) is shown in Fig. 9～10.As can be known from these results, at Ni/Y ₂O ₃Crystal boundary do not separate out the reactant of Fe, but can distinguish the Fe solid solution, partially Ni mutually in.Even can think the crystal boundary of such Fe partially in, the reduction below carrying out also can suppress the change of shape of Ni when handling, thereby suppresses the expansion of the supporting mass that reduction-oxidation circulation thereafter causes.

(experimental example 3)

Mix NiO powder, Y ₂O ₃Powder and Co ₃O ₄Powder accounts for 48 volume %, Y after making (Ni, Co) O after its calcining with the conversion of the total of Ni and Co ₂O ₃Account for 52 volume %, make electrode support (test portion No.10～12) equally with experimental example 1.In addition, in table 3, represent amount (mole %) in the lump with respect to the Co of the total amount of Ni and Co.

About the electrode support of preparation, same with experimental example 1, the linear expansivity in 3 reduction-oxidations circulation is measured, its result is as shown in table 3.In addition, identical with experimental example 1, the conductance in the reducing atmosphere is measured, its result is as shown in table 3.

-Biao 3-

Test portion No.	Co content	Linear expansivity %						Conductance S/cm
									Reduction for the first time	Oxidation for the first time	Reduction for the second time	Oxidation for the second time	Reduction for the third time	Oxidation for the third time
		10	5.0	0.04	0.13	0.05	0.16								0.07	0.16	458
11	10.0							0.04	0.04	0.02	0.06	0.02	0.06	460
		12	30.0	0.09	0.06	0.11	0.08								0.12	0.20	466

Co content is mol% (Co/Co+Ni).

As can be known from the results of Table 3,, be necessary to increase the content of Co, but identical, can suppress the expansion of the supporting mass that causes because of the reduction-oxidation circulation with the situation of Fe or Mn with respect to Fe or Mn.The Co amount is preferably in the scope of 5 to 30 moles of % with the total (Co+Ni) of Ni.

(experimental example 4)

In addition, use the various test portion powder of using in the experimental example 2 (test portion No.5～9), carry out extrusion molding equally, it is carried out drying after making the electrode support body and function formed body of flat with experimental example 2.

The Y that secondly, will contain 8 moles of % ₂O ₃ZrO ₂(YSZ) powder, NiO powder, organic bond (acrylic resin) and solvent (toluene) are modulated into slurry after mixing, and make fuel electrodes layer thin slice with this slurry.In addition, with above-mentioned YSZ powder, organic bond (acrylic resin) and the mixed slurry of toluene are made the solid electrolyte layer thin slice, with the fuel electrodes layer with thin slice and solid electrolyte layer sheet lamination.

This laminated sheet is wound on the above-mentioned electrode support body and function formed body of making, the tabular surface of a side of this formed body is exposed (with reference to figure 1), carry out drying then.

On the contrary, with average grain diameter be the LaCrO of 2 μ m ₃Type oxide powder, organic bond (acrylic resin) and solvent (toluene) are modulated into slurry after mixing, and make the internal connector thin slice with this slurry.With this internal connector with sheet lamination on the flat that exposes of above-mentioned electrode support body and function formed body, make by electrode support body and function formed body, fuel electrodes layer with thin slice, solid electrolyte layer with thin slice, internal connector with laminar sintering thin slice.

Secondly, this sintering thin slice is carried out the processing of place to go adhesive, in atmosphere, calcine simultaneously under 1500 ℃ and obtain sintered body.

It is the La of 2 μ m that the sintered body for preparing is impregnated into by average grain diameter _0.6Sr _0.4Co _0.2Fe _0.8O ₃In the lotion that powder (oxygen utmost point material) and solvent (paraffin) are formed, on the surface that is formed at the solid electrolyte layer on the sintered body, form oxygen utmost point coating, simultaneously above-mentioned lotion is coated on the outer surface of internal connector, the P type semiconductor coating is set, then under 1150 ℃, carry out roasting, make the fuel cell (test portion No.13～17) of structure shown in Figure 1.

In the fuel cell of making, the length of the par A of electrode support is made as 26mm, the length of arcus part B is made as 3.5mm, and thickness is made as 2.8mm; The thickness of fuel electrodes layer is made as 10 μ m, and the thickness of solid electrolyte layer is made as 40 μ m, and the thickness of oxygen utmost point layer is made as 50 μ m, and the thickness of internal connector is made as 50 μ m, and the thickness of p type semiconductor layer is made as 50 μ m.

With electro probe-X-ray microanalysis (EPMA) cross section of the solid electrolyte layer of the fuel cell of acquisition is analyzed, the element that diffuses out from electrode support is confirmed, hydrogen is flow in the interior gas passage of electrode support, make the flow through outside (outside of the oxygen utmost point) of fuel cell of air again, under 850 ℃, made it to generate electricity 100 hours, stop supplies hydrogen makes it natural cooling (making the electrode support oxidation) afterwards.

Secondly, after fuel battery inside pressurizeed it is immersed in water, whether observe gas and leak, slight crack, solid electrolyte layer or the fuel electrodes layer that electrode support or solid electrolyte layer is produced with stereomicroscope peeled off etc. from supporting substrates and observed.Carry out 3 such circulations repeatedly, its result is as shown in table 4.

In addition, make fuel cell after, the power generation performance of 850 ℃ of each fuel cells of (generating for the first time) after following 100 hours is measured, the result is as shown in table 4.

-Biao 4-

Test portion No.	Electrode support test portion No.	Diffusion to solid electrolyte	Have flawless						Power generation performance W/cm 2
										Reduction for the first time	Oxidation for the first time	Reduction for the second time	Oxidation for the second time	Reduction for the third time	Oxidation for the third time
			*13	5	-	Do not have	Have	Have								Have	Have	Have	0.20
14	6	Do not have							Do not have	Do not have	Do not have	Do not have	Do not have	Do not have	0.41
			15	7	Do not have	Do not have	Do not have	Do not have								Do not have	Do not have	Do not have	0.41
16	8	Do not have							Do not have	Do not have	Do not have	Do not have	Do not have	Do not have	0.43
			17	9	Do not have	Do not have	Do not have	Do not have								Do not have	Do not have	Do not have	0.44

^*The outer test portion of the expression scope of the invention.

As can be known from the results of Table 4, in fuel cell of the present invention (test portion No.14～17), do not find that fuel electrodes layer, solid electrolyte layer slight crack occurs or peel off.In addition, also do not spread, power generation performance is also very good, reaches 0.41W/cm at all ²More than.

Claims (10)

1. electrode support for fuel cell, it forms with inorganic aggregate porous body mutually mutually by having the Ni that is made of Ni or NiO, it is characterized in that,

The redox of selecting from the metal group that Fe, Co, Mn constitute is expanded and is suppressed at least a with metal M, be solid-solubilized in described Ni mutually in, perhaps be partially Ni mutually with inorganic aggregate crystal boundary mutually in.

2. electrode support for fuel cell according to claim 1 is characterized in that, described inorganic aggregate is the rare earth element oxide.

3. electrode support for fuel cell according to claim 2 is characterized in that, described inorganic aggregate is Y ₂O ₃

4. electrode support for fuel cell according to claim 1 is characterized in that, it is Mn that described redox expansion suppresses with metal M, with NiMn ₂O ₄, MnYO ₃Or Y ₂NiMnO ₆Form separate out at crystal boundary.

5. electrode support for fuel cell according to claim 1 is characterized in that, it is Fe that described redox expansion suppresses with metal M, with NiFe ₂O ₄Or FeYO ₃Form separate out at crystal boundary.

6. electrode support for fuel cell according to claim 1 is characterized in that described Fe is in the crystal boundary partially.

7. electrode support for fuel cell according to claim 1 is characterized in that, described redox is expanded, and to suppress with metal M be Co, solid solution in Ni mutually in.

8. a solid electrolyte fuel cell is characterized in that, has the structure that stacks gradually fuel electrodes, solid electrolyte and the oxygen utmost point on a face of the described electrode support of claim 1.

9. a stacks of cells is characterized in that, the described a plurality of fuel cell series of claim 8 are formed by connecting.

10. a fuel cell assembly is characterized in that, the described stacks of cells of claim 10 is accommodated in the accommodating container form.

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