JP3199546B2 - Current collector for solid oxide fuel cell and method for producing conductive ceramics - Google Patents
Current collector for solid oxide fuel cell and method for producing conductive ceramicsInfo
- Publication number
- JP3199546B2 JP3199546B2 JP33078793A JP33078793A JP3199546B2 JP 3199546 B2 JP3199546 B2 JP 3199546B2 JP 33078793 A JP33078793 A JP 33078793A JP 33078793 A JP33078793 A JP 33078793A JP 3199546 B2 JP3199546 B2 JP 3199546B2
- Authority
- JP
- Japan
- Prior art keywords
- fuel cell
- temperature
- firing
- current collector
- oxide fuel
- 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.)
- Expired - Fee Related
Links
Classifications
-
- 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
Description
【０００１】[0001]
【産業上の利用分野】本発明は、固体電解質型燃料電池
セル用集電部材および導電性セラミックスの製造方法に
関し、特に低温で焼成することができるとともに、固体
電解質型燃料電池のセパレ−タ、ガスディフ−ザ−、お
よびインタ−コネクタなどの集電部材として好適な固体
電解質型燃料電池セル用集電部材および導電性セラミッ
クスの製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current collector for a solid oxide fuel cell and a method for producing a conductive ceramic, and more particularly to a separator for a solid oxide fuel cell which can be fired at a low temperature. The present invention relates to a current collector for a solid oxide fuel cell suitable as a current collector such as a gas diffuser and an interconnector, and a method for producing a conductive ceramic.
【０００２】[0002]
【従来技術】ランタンクロマイト（ＬａＣｒＯ3 ）系酸
化物は、高温における化学的安定性に優れ、電子伝導性
が大きいことから固体電解質型燃料電池セルのセパレ−
タ、ガスディヒューザ−、およびインタ−コネクタなど
の集電部材として利用されている。2. Description of the Related Art Lanthanum chromite (LaCrO 3 ) -based oxides are excellent in chemical stability at high temperatures and have high electron conductivity.
It is used as a current collecting member such as a heater, a gas diffuser, and an interconnector.
【０００３】図１に、平板形状の固体電解質型燃料電池
セルの概略図を示した。平板型燃料電池セルでは、例え
ばＹ2 Ｏ3 安定化ＺｒＯ2 からなる固体電解質１の一方
にＬａＭｎＯ3 系の空気極２、他方にＮｉ−ジルコニア
等の燃料極３が設けられ、このセル間の接続はＬａＣｒ
Ｏ3 系よりなるセパレ−タ４により行われている。燃料
電池セルにおいては、空気極側に酸素を含有するガスた
とえば空気を流し、燃料極側に燃料例えば水素ガスを流
しながら、１０００〜１０５０℃の温度で発電する。上
述のセパレ−タ材料としては、ＣａＯあるいはＳｒＯを
固溶したＬａＣｒＯ3 系材料が利用される。FIG. 1 is a schematic view of a flat solid electrolyte fuel cell. In a flat fuel cell, for example, a LaMnO 3 -based air electrode 2 is provided on one side of a solid electrolyte 1 made of Y 2 O 3 stabilized ZrO 2, and a fuel electrode 3 such as Ni-zirconia is provided on the other side. Connection is LaCr
This is performed by a separator 4 composed of an O 3 system. In the fuel cell, power is generated at a temperature of 1000 to 1050 ° C. while flowing a gas containing oxygen, such as air, on the air electrode side and flowing a fuel, for example, hydrogen gas on the fuel electrode side. As the above-mentioned separator material, a LaCrO 3 material in which CaO or SrO is dissolved is used.
【０００４】[0004]
【発明が解決しようとする問題点】ＬａＣｒＯ3 系材料
は陽イオンの拡散速度が遅いことに加えて、焼結過程に
おいて材料中からＣｒ成分が揮発し、粒子の接触部（ネ
ック部）にＣｒ2 Ｏ3 として凝縮堆積して焼結を阻害す
る。このため、大気中では２０００℃以上の高温で焼結
させるか、あるいは還元性雰囲気でこのＣｒ2 Ｏ3 の蒸
発凝縮を抑制しながら焼結させることが必要である。ま
た、焼成雰囲気を制御して焼成しても１８００℃以上の
高温で焼成することが必要である。このような高温での
材料の作製は、経済的な観点から燃料電池セルの量産を
著しく困難にさせている。Problems to be Solved by the Invention In addition to the slow diffusion rate of cations, the LaCrO 3 -based material volatilizes the Cr component from the material during the sintering process, and causes the Cr contact at the contact portion (neck portion) of the particles. It condenses and deposits as 2 O 3 and hinders sintering. For this reason, it is necessary to perform sintering at a high temperature of 2000 ° C. or higher in the atmosphere, or to perform sintering in a reducing atmosphere while suppressing the evaporation and condensation of Cr 2 O 3 . Further, it is necessary to perform firing at a high temperature of 1800 ° C. or more even when firing is performed while controlling the firing atmosphere. Production of materials at such a high temperature makes mass production of fuel cells extremely difficult from an economic viewpoint.
【０００５】また、一方低温でＬａＣｒＯ3 系材料を得
るための方法として、円筒型燃料電池セルの作製におい
ては電気化学的気相合成（ＥＶＤ）法が適用されてい
る。しかしながら、この方法は１４００℃と比較的低温
でＬａＣｒＯ3 系材料が作製されるものの、ＬａＣｒＯ
3 の成長速度が遅いため量産性に欠ける欠点がある。し
かも、出発原料として極めて高価な金属塩化物を使用す
る必要があるため経済的にも問題がある。On the other hand, as a method for obtaining a LaCrO 3 -based material at a low temperature, an electrochemical vapor deposition (EVD) method has been applied in the production of a cylindrical fuel cell. However, this method produces a LaCrO 3 -based material at a relatively low temperature of 1400 ° C.
There is a disadvantage that mass production is lacking due to the slow growth rate of 3 . In addition, it is economically problematic because extremely expensive metal chlorides must be used as starting materials.
【０００６】本発明は、燃料電池セルの集電部材に用い
られ、低温で安価に作製することのできる新規ＬａＣｒ
Ｏ3 系材料を提供することを目的とするものである。The present invention relates to a novel LaCr which can be used at low temperature and inexpensively and is used for a current collecting member of a fuel cell.
An object is to provide an O 3 -based material.
【０００７】[0007]
【問題点を解決するための手段】本発明者等は、上記目
的に対して検討を重ねた結果、ＬａＣｒＯ3 のうちのＬ
ａをＳｒ、Ｂａ、Ｃａなどにより特定の量で置換し、且
つＣｒの一部を特定量のＣｕで置換するとともに、Ｍｇ
などの金属により置換することにより低温での合成が可
能となることを見いだし本発明に至ったのである。Means for Solving the Problems The present inventors have repeatedly studied the above object, and as a result, have found that L out of LaCrO 3
a is replaced with a specific amount by Sr, Ba, Ca, etc., and a part of Cr is replaced with a specific amount of Cu.
It has been found that substitution at a low temperature makes it possible to synthesize at a low temperature, leading to the present invention.
【０００８】即ち、本発明の固体電解質型燃料電池セル
用集電部材は、組成が下記化１That is, the current collector for a solid oxide fuel cell according to the present invention has the following composition.
【０００９】[0009]
【化１】 Embedded image
【００１０】で表され、式中、ＡはＳｒ、ＢａおよびＣ
ａから選ばれる少なくとも１種の元素、ＢはＭｇ、Ｚ
ｒ、Ａｌ、Ｍｎ、Ｆｅ、Ｃｅ、ＣｏおよびＮｉの群から
選ばれる少なくとも１種の元素からなるとともに、ｘ、
ｙ、ｋ、ｍおよびｎが ０．０５ ≦ｘ＋ｎ≦０．３０ ０．００１≦ ｙ ≦０．０５ ０．９０ ≦ ｋ ≦１．０５ ０．００１≦ ｍ ≦０．１０ を満足するとともに開気孔率が１％以下の導電性セラミ
ックスからなることを特徴とする。Wherein A is Sr, Ba and C
at least one element selected from a, B is Mg, Z
and at least one element selected from the group consisting of r, Al, Mn, Fe, Ce, Co and Ni;
y, k, m and n satisfy 0.05 ≦ x + n ≦ 0.30 0.001 ≦ y ≦ 0.05 0.90 ≦ k ≦ 1.05 0.001 ≦ m ≦ 0.10 and open pores It is characterized by being made of a conductive ceramic having a ratio of 1% or less.
【００１１】さらに、本発明の導電性セラミックスを製
造する方法は、上記化１で示される組成を満足するよう
に調合された金属化合物からなる混合粉末を１０００℃
以上の温度で仮焼し固溶体化した後、該固溶体を粉砕を
所定の形状に成形後、１３００℃以上の温度で焼成する
ことを特徴とするものである。Further, the method for producing a conductive ceramic according to the present invention comprises the steps of: mixing a mixed powder of a metal compound prepared so as to satisfy the composition represented by the above formula 1 at 1000 ° C.
After calcining at the above temperature to form a solid solution, the solid solution is pulverized into a predetermined shape, and then fired at a temperature of 1300 ° C. or more.
【００１２】本発明の導電性セラミックスにおいて、
ｘ、ｙ、ｋ、ｍ、ｎを上記の範囲に限定したのは、ｘ＋
ｎが０．０５より小さいか、あるいはこれらが０．３よ
り大きいとジルコニアなどの固体電解質との熱膨張係数
の差が１０％を越え、セル構造を組んだ場合、発電時に
おいて昇温、冷却により熱応力が発生してセルが破壊す
るためである。また、ｙが０では焼結体が十分に緻密化
せず、１％以上の開気孔率が残存し、０．０５を越える
と発電時において１０００℃で長期間使用した場合、相
分離をおこしＣａ濃度の高い相（Ｃａp （ＣｒＯ）q 相
（ここでｐ，ｑは整数）と思われる）が析出し発電特性
が劣化するためである。さらに、ＡサイトとＢサイトの
原子の存在比（不定比量）ｋが０．９より小さいとＣｒ
2 Ｏ3 が析出し、電気伝導度が低下し、１．０５を越え
るとＬａ2 Ｏ3 が析出し空気中の水分を吸収して材料が
分解する。さらに、ｍが０（ゼロ）では、焼結体が十分
に緻密化せず、１％以上の開気孔率が残り、０．１を越
えるとＣｕＯが析出し電気絶縁性が劣化する。In the conductive ceramic of the present invention,
x, y, k, m, and n are limited to the above ranges because x +
If n is smaller than 0.05 or larger than 0.3, the difference in thermal expansion coefficient from a solid electrolyte such as zirconia exceeds 10%, and when a cell structure is formed, the temperature rises and cools during power generation. This causes thermal stress to occur and the cell is broken. On the other hand, if y is 0, the sintered body is not sufficiently densified, and an open porosity of 1% or more remains. If it exceeds 0.05, phase separation occurs at power generation at 1000 ° C. for a long time. high phase of Ca concentration is due to deterioration is precipitated power generation characteristics (p, Ca p (CrO) q-phase (here q is seems an integer)). Further, if the abundance ratio (non-stoichiometric amount) k of atoms at the A site and the B site is smaller than 0.9, Cr
2 O 3 is precipitated, and the electric conductivity is reduced. When the electric conductivity exceeds 1.05, La 2 O 3 is precipitated and absorbs moisture in the air to decompose the material. Further, when m is 0 (zero), the sintered body is not sufficiently densified, and an open porosity of 1% or more remains. When it exceeds 0.1, CuO is precipitated and electric insulation is deteriorated.
【００１３】なお、本発明の導電性セラミックスは、そ
の開気孔率が１％以下、特に０．５％以下であることも
重要である。これは、かかる導電性セラミックスを燃料
電池の集電部材として用いる場合、集電部材の一方の面
は水素ガスに他方の面は酸素ガスに接しており、これら
のガスは集電部材を介して完全に分離されることが必要
であり、集電部材自体が高気密性を有することが要求さ
れるためである。It is important that the conductive ceramic of the present invention has an open porosity of 1% or less, particularly 0.5% or less. This is because when such a conductive ceramic is used as a current collecting member of a fuel cell, one surface of the current collecting member is in contact with hydrogen gas and the other surface is in contact with oxygen gas, and these gases pass through the current collecting member. This is because it is necessary to be completely separated, and it is required that the current collecting member itself has high airtightness.
【００１４】本発明におけるｘ、ｙ、ｋ、ｍおよびｎの
好ましい組成範囲は、 ０．１０ ≦ ｘ＋ｎ ≦ ０．２０ ０．００１≦ ｙ ≦ ０．０２ ０．９５ ≦ ｋ ≦ １．０ ０．０３ ＜ ｍ ≦ ０．１０ である。In the present invention, the preferable composition ranges of x, y, k, m and n are as follows: 0.10 ≦ x + n ≦ 0.20 0.001 ≦ y ≦ 0.02 0.95 ≦ k ≦ 1.0. 03 <m ≦ 0.10.
【００１５】本発明の上記導電性セラミックスを製造す
るには、前記化１を構成するＬａ2Ｏ3 、Ｃｒ2 Ｏ3 、
ＣａＣＯ3 、ＣｕＯ、ＢａＣＯ3 、ＭｇＣＯ3 、ＺｒＯ
2 などの各金属元素の酸化物粉末、あるいは熱処理によ
り酸化物を形成し得る水酸化物や炭酸化物が出発原料と
して使用される。これらの原料粉末を用いて緻密な導電
性セラミックスを作製するには、これらの原料粉末を一
度仮焼して固溶体粉末を作製しないと緻密な焼結体が得
られない。燃料電池セル用の集電部材は前述したように
緻密質で開気孔が存在してはならない。In order to produce the conductive ceramic of the present invention, La 2 O 3 , Cr 2 O 3 ,
CaCO 3 , CuO, BaCO 3 , MgCO 3 , ZrO
An oxide powder of each metal element such as 2 , or a hydroxide or carbonate that can form an oxide by heat treatment is used as a starting material. In order to produce dense conductive ceramics using these raw material powders, a dense sintered body cannot be obtained unless these raw material powders are calcined once to produce a solid solution powder. As described above, the current collecting member for the fuel cell unit must be dense and have no open pores.
【００１６】従って、酸化物などの各金属化合物を化１
の組成となるように秤量混合した後、この混合粉末を１
０００℃以上の温度で一旦仮焼して固溶体化処理し、こ
の固溶体を粉砕した後、これを所定の形状に成形し、そ
の成形体を１３００℃以上の温度で焼成することにより
緻密化することができる。Accordingly, each metal compound such as an oxide is converted to
After weighing and mixing so as to obtain the composition of
Temporarily calcining at a temperature of 000 ° C. or higher to form a solid solution, pulverizing this solid solution, forming it into a predetermined shape, and firing the formed body at a temperature of 1300 ° C. or higher to densify Can be.
【００１７】なお、焼成の際、焼成炉内で成形体が接す
る部分、例えば保持具などの焼成用治具を、純度９９％
以上のＡｌ2 Ｏ3 、ＭｇＯの焼結体や、ＣａＯ、Ｍｇ
Ｏ、Ｙ2 Ｏ3 、Ｙｂ2 Ｏ3 のうち少なくとも１種を含有
するＺｒＯ2 焼結体のいずれかにより構成することが望
ましい。これは、ＬａＣｒＯ3 系固溶体材料は不純物に
敏感で、焼成用治具などを通じ、例えばＳｉ、Ｔｉ等の
不純物が材料中に拡散すると、これらの不純物が焼結助
剤的作用をなすため、材料中で焼結性が不均一になり材
料が大きく変形してしまう。これを避けるため、上述し
たような高純度でＳｉやＴｉを含まない保持治具を用い
て焼成することが必要となるのである。During firing, a portion of the firing body in the firing furnace, for example, a firing jig such as a holder, is fixed at a purity of 99%.
The above sintered bodies of Al 2 O 3 and MgO, CaO, Mg
It is desirable that the ZrO 2 sintered body contains at least one of O, Y 2 O 3 and Yb 2 O 3 . This is because the LaCrO 3 -based solid solution material is sensitive to impurities, and when impurities such as Si and Ti diffuse into the material through a firing jig or the like, these impurities act as a sintering aid. In this case, the sinterability becomes uneven and the material is greatly deformed. In order to avoid this, it is necessary to use a high-purity holding jig that does not contain Si or Ti as described above.
【００１８】[0018]
【作用】ＬａＣｒＯ3 系材料は、結晶内の陽イオンの拡
散速度が遅いことに加えて、Ｃｒ成分が優先的に蒸発し
やすく、大気中ではこれが焼結の際粒子の接触部に凝縮
してＣｒ2 Ｏ3 として堆積し、陽イオンの拡散を阻害し
焼結性を悪くする、ＬａＣｒＯ3 系材料では焼結はいわ
ゆる蒸発凝縮機構が支配的である。In the LaCrO 3 material, in addition to the slow diffusion rate of cations in the crystal, the Cr component is liable to evaporate preferentially, and in the atmosphere, this condenses on the contact portion of the particles during sintering. In a LaCrO 3 -based material, which is deposited as Cr 2 O 3 and inhibits diffusion of cations to deteriorate sinterability, the so-called evaporative condensation mechanism is dominant in sintering.
【００１９】それに対して、本発明の材料は、ＬａをＳ
ｒ、Ｃａ、Ｍｇなどの他の陽イオンで置換し、且つＣａ
を定比より過剰に添加することにより１１００〜１２０
０℃付近でＣａを主成分とする液相が生成され、これに
より粒界相における陽イオンの拡散速度が大きくなり、
焼結性が大きく向上する。また、粒界が液相で覆われて
いるためにＣｒ成分の蒸発を抑制することもできる。さ
らに、本発明の構成によれば、陽イオンの拡散速度の速
いＣｕで、Ｂサイトを置換することによりＬａＣｒＯ3
の焼結性が大きく向上する。On the other hand, in the material of the present invention, La
substituted with other cations such as r, Ca, Mg, and Ca
Is added in excess of the stoichiometric ratio to obtain 1100 to 120
At around 0 ° C., a liquid phase containing Ca as a main component is generated, whereby the diffusion rate of cations in the grain boundary phase increases,
Sinterability is greatly improved. Further, since the grain boundaries are covered with the liquid phase, the evaporation of the Cr component can be suppressed. Further, according to the configuration of the present invention, LaCrO 3 is obtained by replacing the B site with Cu having a high cation diffusion rate.
Greatly improves the sinterability of the steel.
【００２０】しかし、本材料は電気伝導性を有すること
が必要であり、焼成後にはペロブスカイト構造の結晶か
らなるものであるが、過剰のＣａ量が多すぎたり、Ｃｕ
の添加量が多くＣｕＯが析出すると、燃料電池の作動温
度である１０００℃で長時間焼鈍すると相分離を起こし
電気伝導性の低い相が出現し発電特性を低下させる結果
となる。そのため、Ｃａの過剰量（ｚ）の上限を０．０
５、またＣｕの置換量（ｍ）の上限を０．１０に設定し
た。However, this material is required to have electric conductivity, and is composed of crystals having a perovskite structure after firing.
When a large amount of CuO is precipitated and CuO precipitates, annealing at 1000 ° C., which is the operating temperature of the fuel cell, for a long time causes phase separation, resulting in the appearance of a phase with low electric conductivity, resulting in a decrease in power generation characteristics. Therefore, the upper limit of the excess amount (z) of Ca is set to 0.0
5, and the upper limit of the substitution amount (m) of Cu was set to 0.10.
【００２１】さらに、燃料電池セルにおいて集電部材
は、固体電解質に対して積層されていることから、高温
作動時において熱膨張係数が極度に異なると集電部材が
剥離し発電出力の低下やセルの破壊などを招く場合もあ
る。よって、集電部材と固体電解質との熱膨張差はセル
の信頼性の点からは±１０％以内であることが必要であ
る。このような観点から前記化１におけるｘ、ｎを決定
した。Further, in the fuel cell, since the current collecting member is laminated on the solid electrolyte, if the coefficient of thermal expansion is extremely different at the time of high-temperature operation, the current collecting member is peeled off, and the power generation output is reduced and the cell power is reduced. In some cases. Therefore, the difference in thermal expansion between the current collecting member and the solid electrolyte needs to be within ± 10% from the viewpoint of cell reliability. From such a viewpoint, x and n in Chemical Formula 1 were determined.
【００２２】また、本発明の導電性セラミックスを作製
する場合、酸化物、水酸化物あるいは炭酸化物の混合粉
末が用いられるが、これらの混合粉末を直接焼結させる
と水酸化物あるいは炭酸化物が焼成中に分解が起こり焼
結体中に大きな気孔を残したりする。また、これに加え
て単体から固溶体への合成プロセスにおいて、モラ−ボ
リュ−ムの変化が大きく焼成中に焼結体が破壊したり、
あるいは焼結体中に多数の開気孔が残ったりもする。こ
のため、本発明によれば、一旦固相反応により固溶体を
生成させた後に、その固溶体粉末を焼結させる２つの工
程に分けることが重要となる。具体的には固溶体化処理
を１０００℃以上で行い、その後、１３００℃以上の低
温で焼成すれば開気孔のない焼結体を得ることができ
る。When producing the conductive ceramics of the present invention, a mixed powder of an oxide, a hydroxide or a carbonate is used. Decomposition occurs during firing, leaving large pores in the sintered body. In addition, in the synthesis process from a simple substance to a solid solution, the change in mora volume is large and the sintered body is broken during firing,
Alternatively, many open pores may remain in the sintered body. For this reason, according to the present invention, it is important to divide the process into two steps in which a solid solution is once generated by a solid-phase reaction and then the solid solution powder is sintered. Specifically, if the solid solution treatment is performed at a temperature of 1000 ° C. or higher, and then the firing is performed at a low temperature of 1300 ° C. or higher, a sintered body without open pores can be obtained.
【００２３】また、焼成中材料が純度の低い保持治具に
接すると不純物が材料中に拡散し、焼結が均一に起こら
ず焼結体が変形する。特に、本材料は焼成温度において
は液相が生じているためその影響は大きい。特に、治具
に含まれるＳｉ、Ｔｉ等の不純物が材料中への拡散が著
しく、またそれによる変形が著しいことが判明した。こ
れを防ぐために、種々の保持治具を検討した結果、純度
９９％以上のＡｌ2Ｏ3 あるいはＭｇＯの焼結体、Ｃａ
Ｏ、ＭｇＯ、Ｙ2 Ｏ3 、Ｙｂ2 Ｏ3 のうち少なくとも一
つを含有するＺｒＯ2 焼結体のいずれかを保持治具とし
て用いて作製すればよいことがわかった。Further, when the material comes into contact with the holding jig having low purity during the firing, impurities diffuse into the material, and sintering does not occur uniformly and the sintered body is deformed. In particular, since the present material has a liquid phase at the firing temperature, the effect is significant. In particular, it was found that impurities such as Si and Ti contained in the jig diffused remarkably into the material, and the resulting deformation was remarkable. As a result of studying various holding jigs to prevent this, a sintered body of Al 2 O 3 or MgO having a purity of 99% or more, Ca
It has been found that the ZrO 2 sintered body containing at least one of O, MgO, Y 2 O 3 , and Yb 2 O 3 may be manufactured using a holding jig.
【００２４】[0024]
実施例１ 市販の純度９９．９％のＬａ2 Ｏ3 、ＳｒＣＯ3 、Ｃａ
ＣＯ3 、ＢａＣＯ3 、ＣｕＯ、Ｃｒ2 Ｏ3 を表１、表２
に示すような所定の組成になるように調合した後、この
混合粉末を９００〜１４５０℃で２〜１０時間焼鈍して
固相反応（仮焼）を行わせた。仮焼物のＸ線回折の結
果、１０００℃以上で仮焼した試料はいずれもＬａＣｒ
Ｏ3 系のペロブスカイト型結晶を有するものであった
が、仮焼温度が１０００℃未満の試料では未反応のＬａ
2 Ｏ3 、Ｃｒ2 Ｏ3 が残っていた。Example 1 Commercially available La 2 O 3 , SrCO 3 , and Ca having a purity of 99.9%
Tables 1 and 2 show CO 3 , BaCO 3 , CuO and Cr 2 O 3.
After the mixture was prepared so as to have a predetermined composition, the mixed powder was annealed at 900 to 1450 ° C. for 2 to 10 hours to perform a solid phase reaction (calcination). As a result of the X-ray diffraction of the calcined material, all of the samples calcined at 1000 ° C. or higher were LaCr
A sample having an O 3 -based perovskite crystal but having a calcining temperature of less than 1000 ° C. had unreacted La.
2 O 3 and Cr 2 O 3 remained.
【００２５】その後、この仮焼物をジルコニアボ−ルを
用いて１０〜２４時間粉砕した後、断面が５ｍｍ×５ｍ
ｍ，長さ４５ｍｍの四角柱に成形し、大気中１２５０〜
１６５０℃の温度で焼成した。なお、焼成時には純度９
９．１％の原料を用いて作製したＡｌ2 Ｏ3 焼結体を保
持具として用いた。Thereafter, the calcined product was pulverized with a zirconia ball for 10 to 24 hours, and the cross section was 5 mm × 5 m.
m, formed into a 45 mm long square pole,
It was fired at a temperature of 1650 ° C. At the time of firing, the purity is 9
An Al 2 O 3 sintered body produced using 9.1% raw material was used as a holder.
【００２６】得られた焼結体に対してアルキメデス法に
より試料の開気孔率の測定を行い、焼結性を判断した。
また、この焼結体から大きさ１．５ｍｍ×１．５ｍｍ
で、長さ１０ｍｍと２０ｍｍの試料片を作製し、前者の
試料について室温から１０００℃までの熱膨張係数の測
定を、後者の試料について電気伝導度の測定を行った。
さらに、上記の焼結体を大気中１０００℃で３００時間
焼鈍した後、Ｘ線回折とＥＰＭＡ分析を行い結晶相の安
定性を調べた。各測定の結果は表１、表２に示した。With respect to the obtained sintered body, the open porosity of the sample was measured by the Archimedes method, and the sinterability was determined.
The size of the sintered body is 1.5 mm × 1.5 mm.
Then, sample pieces having a length of 10 mm and 20 mm were prepared, and the thermal expansion coefficient of the former sample from room temperature to 1000 ° C. was measured, and the electrical conductivity of the latter sample was measured.
Further, after the above sintered body was annealed in the air at 1000 ° C. for 300 hours, X-ray diffraction and EPMA analysis were performed to examine the stability of the crystal phase. The results of each measurement are shown in Tables 1 and 2.
【００２７】[0027]
【表１】 [Table 1]
【００２８】[0028]
【表２】 [Table 2]
【００２９】表１、表２に示す結果によれば、ｘ＋ｎが
０．０５より小さいか、または０．３０より大きいと固
体電解質との熱膨張係数の差が１０％より大きくなっ
た。ｙが０．０５より多くなると、長時間の焼鈍で相分
離し、Ｃａp （ＣｒＯ）q 相と思われる相が析出した。
また、ＥＰＭＡ分析においてＣａが濃縮した相が観察さ
れた。ＡサイトとＢサイトの原子の存在比（不定比量）
ｋが０．９０より小さいとＣｒ2 Ｏ3 が析出した。逆
に、ｋが１．０５より多いとＬａ2 Ｏ3 が析出し試料が
短時間に分解した。ｍが０（ゼロ）では焼結体が十分に
緻密化せず、１％以上の開気孔率が残存した。ｍが０．
１０より多くなるとＣｕＯ相が析出し、電気特性が劣化
した。また、仮焼温度、または焼成温度がそれぞれ１０
００℃および１３００℃より低いと開気孔が存在した。According to the results shown in Tables 1 and 2, when x + n is smaller than 0.05 or larger than 0.30, the difference in the coefficient of thermal expansion with the solid electrolyte is larger than 10%. When y is more than 0.05, phase separation in the long annealing, phase seems to Ca p (CrO) q-phase is precipitated.
Further, in the EPMA analysis, a phase in which Ca was concentrated was observed. Atom abundance ratio between A site and B site (non-stoichiometric amount)
If k is smaller than 0.90, Cr 2 O 3 was precipitated. Conversely, when k was more than 1.05, La 2 O 3 was precipitated and the sample was decomposed in a short time. When m was 0 (zero), the sintered body was not sufficiently densified, and an open porosity of 1% or more remained. m is 0.
When it was more than 10, a CuO phase was precipitated, and the electrical characteristics were deteriorated. The calcination temperature or the calcination temperature is 10
Below 00 ° C. and 1300 ° C., open pores were present.
【００３０】実施例２ 市販の純度９９．９％のＬａ2 Ｏ3 、ＣａＣＯ3 、Ｓｒ
ＣＯ3 、ＢａＣＯ3 、ＣｕＯ、Ｃｒ2 Ｏ3 、ＭｇＯ、Ａ
ｌ2 Ｏ3 、ＭｎＯ、ＦｅＯ、ＮｉＯ、ＺｒＯ2、ＣｅＯ
2 、ＣｏＯの各粉末を表３、表４に示すような所定の組
成になるように調合した後、実施例１と同様にして仮
焼、成形体、焼成を行った。なお、焼成時には純度９
９．５％の原料を用いて作製したＭｇＯ焼結体を保持具
として用いた。Example 2 La 2 O 3 , CaCO 3 , Sr having a purity of 99.9% commercially available
CO 3 , BaCO 3 , CuO, Cr 2 O 3 , MgO, A
l 2 O 3 , MnO, FeO, NiO, ZrO 2 , CeO
2. Each powder of CoO was prepared so as to have a predetermined composition as shown in Tables 3 and 4, and then calcined, formed and fired in the same manner as in Example 1. At the time of firing, the purity is 9
An MgO sintered body produced using a 9.5% raw material was used as a holder.
【００３１】得られた焼結体に対しては、実施例１と同
様な方法により開気孔率、熱膨張係数、電気伝導度、結
晶相の変化を調べ、結果を表３、表４に示した。With respect to the obtained sintered body, changes in open porosity, thermal expansion coefficient, electric conductivity, and crystal phase were examined in the same manner as in Example 1, and the results are shown in Tables 3 and 4. Was.
【００３２】[0032]
【表３】 [Table 3]
【００３３】[0033]
【表４】 [Table 4]
【００３４】表３、表４の結果によれば、ｘ＋ｎが０．
０５より小さいか、または０．３より大きいと固体電解
質との熱膨張係数の差が１０％より大きくなることがわ
かる。また、仮焼温度及び焼成温度がそれぞれ１０００
℃および１３００℃より低いと開気孔が存在した。According to the results shown in Tables 3 and 4, x + n is equal to 0.
It can be seen that if the value is smaller than 05 or larger than 0.3, the difference in thermal expansion coefficient with the solid electrolyte becomes larger than 10%. Further, the calcining temperature and the baking temperature are each 1000.
C. and below 1300.degree. C., open pores were present.
【００３５】実施例３ 上記実施例中のＮｏ．４，２３，３６，４６を用いて、
図１に示した構造の大きさ５０ｍｍ×５０ｍｍのセパレ
−タを作製した。各セパレ−タを構成する焼結体の結晶
粒子径は約３μｍであった。Embodiment 3 No. 3 in the above embodiment. Using 4,23,36,46,
A separator 50 mm × 50 mm having the structure shown in FIG. 1 was produced. The crystal grain size of the sintered body constituting each separator was about 3 μm.
【００３６】次に、市販の純度９９．９％の８ｍｏｌ％
Ｙ2 Ｏ3 −９２ｍｏｌ％ＺｒＯ2 粉末を用い、理論密度
比９９．３％の緻密な厚み０．３５ｍｍの固体電解質板
を作製した。Next, a commercially available 8 mol% of 99.9% purity.
Y 2 O 3 with -92mol% ZrO 2 powder, to prepare a solid electrolyte plate of the theoretical density ratio 99.3% dense thickness 0.35 mm.
【００３７】そして、この固体電解質板の一方の面に３
０μｍの厚みに７０重量％ＮｉＯ−３０重量％ジルコニ
ア（８ｍｏｌ％Ｙ2 Ｏ3 を含有）の混合粉末を塗布し１
４００Ｃで２時間焼き付け燃料極とした。その後、他方
の面にＬａを１５原子％のＳｒで置換したＬａＭｎＯ3
粉末を３０μｍの厚みに塗布し、１２００Ｃで２時間焼
き付け空気極とした。これを上記のセパレ−タで挟み空
気極側に酸素ガスを燃料極側に水素ガスを流し１０００
℃で３００時間連続発電し、発電時の出力密度を測定
し、その結果を図２に示した。[0037] Then, one surface of the solid electrolyte plate is
A mixed powder of 70 wt% NiO-30 wt% zirconia (containing 8 mol% Y 2 O 3 ) was applied to a thickness of 0 μm, and 1
The fuel electrode was baked at 400 C for 2 hours. Then, LaMnO 3 in which La was substituted with 15 atomic% of Sr was formed on the other surface.
The powder was applied to a thickness of 30 μm and baked at 1200 C for 2 hours to form an air electrode. This is sandwiched between the separators, and oxygen gas and hydrogen gas are supplied to the air electrode side and the fuel electrode side, respectively.
The power was continuously generated at 300C for 300 hours, and the output density during power generation was measured. The results are shown in FIG.
【００３８】図２によれば、本発明以外のＮｏ．３６、
４６は低出力でまた時間と共に出力密度は減少したが、
本発明のＮｏ．４，２３は安定した発電特性を示すこと
が分かる。これより、本発明の導電性セラミックスが固
体電解質型燃料電池セルの集電部材として好適なもので
あることがわかる。According to FIG. 36,
46 has low power and the power density decreased with time,
No. of the present invention. 4, 23 show stable power generation characteristics. This indicates that the conductive ceramics of the present invention is suitable as a current collecting member of a solid oxide fuel cell.
【００３９】[0039]
【発明の効果】以上の説明で明らかなように、本発明の
導電性セラミッスは、従来のＬａＣｒＯ3 系材料に比較
して、低温での焼成により緻密化することができる。そ
のため、燃料電池セルの集電部材として使用した場合に
セルの作製の製造プロセスにおいて経済性に優れる。ま
た、焼結体の緻密性に優れるため集電部材に使用した場
合、単位面積当たりの出力が高く、長期安定性に優れた
セルを提供できる。As is apparent from the above description, the conductive ceramics of the present invention can be densified by firing at a lower temperature than conventional LaCrO 3 -based materials. Therefore, when used as a current collecting member of a fuel cell, it is excellent in economical efficiency in the manufacturing process of cell production. Further, when the sintered body is used for a current collecting member because of its excellent denseness, a cell having high output per unit area and excellent long-term stability can be provided.
【図１】平板形状の固体電解質型燃料電池セルの概略図
である。FIG. 1 is a schematic view of a plate-shaped solid oxide fuel cell.
【図２】実施例３における発電時間と出力密度との関係
を示した図である。FIG. 2 is a diagram illustrating a relationship between a power generation time and an output density according to a third embodiment.
１ 固体電解質 ２ 空気極 ３ 燃料極 ４ セパレ−タ DESCRIPTION OF SYMBOLS 1 Solid electrolyte 2 Air electrode 3 Fuel electrode 4 Separator
Claims (2)
る少なくとも１種の元素、ＢはＭｇ、Ｚｒ、Ａｌ、Ｍ
ｎ、Ｆｅ、Ｃｅ、ＣｏおよびＮｉの群から選ばれる少な
くとも１種の元素からなるとともに、ｘ、ｙ、ｋ、ｍお
よびｎが ０．０５ ≦ｘ＋ｎ≦０．３０ ０．００１≦ ｙ ≦０．０５ ０．９０ ≦ ｋ ≦１．０５ ０．００１≦ ｍ ≦０．１０ を満足するとともに開気孔率が１％以下の導電性セラミ
ックスからなることを特徴とする固体電解質型燃料電池
セル用集電部材。1. A composition represented by (La 1-x A x Ca y) k (Cr 1-mn Cu m B n) O 3 ± δ, in the formula, A at least is selected from Sr, Ba and Ca One element, B is Mg, Zr, Al, M
n, Fe, Ce, Co, and Ni are made of at least one element selected from the group, and x, y, k, m, and n are 0.05 ≦ x + n ≦ 0.30 0.001 ≦ y ≦ 0. 05 0.90 ≤ k ≤ 1.05 0.001 ≤ m ≤ 0.10 and a current collector for a solid oxide fuel cell, characterized by being made of a conductive ceramic having an open porosity of 1% or less. Element.
る少なくとも１種の元素、ＢはＭｇ、Ｚｒ、Ａｌ、Ｍ
ｎ、Ｆｅ、Ｃｅ、ＣｏおよびＮｉの群から選ばれる少な
くとも１種の元素からなるとともに、ｘ、ｙ、ｋ、ｍお
よびｎが、 ０．０５ ≦ｘ＋ｎ≦０．３０ ０．００１≦ ｙ ≦０．０５ ０．９０ ≦ ｋ ≦１．０５ ０．００１≦ ｍ ≦０．１０ を満足するように調合された金属化合物からなる混合粉
末を１０００℃以上の温度で仮焼し固溶体化した後、該
固溶体を粉砕して所定の形状に成形後、１３００℃以上
の温度で焼成することを特徴とする導電性セラミックス
の製造方法。2. A composition represented by (La 1-x A x Ca y) k (Cr 1-mn Cu m B n) O 3 ± δ, in the formula, A at least is selected from Sr, Ba and Ca One element, B is Mg, Zr, Al, M
x, y, k, m and n are at least one element selected from the group consisting of n, Fe, Ce, Co and Ni, and 0.05 ≦ x + n ≦ 0.30 0.001 ≦ y ≦ 0 The mixed powder composed of the metal compound prepared so as to satisfy the condition of 0.055 0.90 ≦ k ≦ 1.05 0.001 ≦ m ≦ 0.10 is calcined at a temperature of 1000 ° C. or more to form a solid solution. A method for producing a conductive ceramic, comprising: pulverizing a solid solution into a predetermined shape, followed by firing at a temperature of 1300 ° C. or higher.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33078793A JP3199546B2 (en) | 1993-12-27 | 1993-12-27 | Current collector for solid oxide fuel cell and method for producing conductive ceramics |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33078793A JP3199546B2 (en) | 1993-12-27 | 1993-12-27 | Current collector for solid oxide fuel cell and method for producing conductive ceramics |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07187768A JPH07187768A (en) | 1995-07-25 |
| JP3199546B2 true JP3199546B2 (en) | 2001-08-20 |
Family
ID=18236547
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP33078793A Expired - Fee Related JP3199546B2 (en) | 1993-12-27 | 1993-12-27 | Current collector for solid oxide fuel cell and method for producing conductive ceramics |
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| Country | Link |
|---|---|
| JP (1) | JP3199546B2 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6811914B2 (en) * | 2001-04-27 | 2004-11-02 | Air Products And Chemicals, Inc. | Electrochemical solid-state device comprising b-site rich lanthanum calcium manganite |
| JP4528021B2 (en) * | 2004-04-27 | 2010-08-18 | 新日本製鐵株式会社 | Oxide ion mixed conductor, composite structure, oxygen separation device, and chemical reaction device |
| CN116375469B (en) * | 2023-03-31 | 2024-05-03 | 中国矿业大学 | Method for solid phase synthesis of proton conductor electrolyte ceramic powder |
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