JPH11233121A - Air electrode material for molten carbonate fuel cell and its manufacture - Google Patents

Air electrode material for molten carbonate fuel cell and its manufacture

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Publication number
JPH11233121A
JPH11233121A JP10054360A JP5436098A JPH11233121A JP H11233121 A JPH11233121 A JP H11233121A JP 10054360 A JP10054360 A JP 10054360A JP 5436098 A JP5436098 A JP 5436098A JP H11233121 A JPH11233121 A JP H11233121A
Authority
JP
Japan
Prior art keywords
air electrode
particles
nickel
electrode material
cobalt
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP10054360A
Other languages
Japanese (ja)
Inventor
Takehisa Fukui
武久 福井
Hajime Okawa
元 大川
Makio Naito
牧男 内藤
Tei Hotta
禎 堀田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
YOYU TANSANENGATA NENRYO DENCH
YOYU TANSANENGATA NENRYO DENCHI HATSUDEN SYSTEM GIJUTSU KENKYU KUMIAI
Original Assignee
YOYU TANSANENGATA NENRYO DENCH
YOYU TANSANENGATA NENRYO DENCHI HATSUDEN SYSTEM GIJUTSU KENKYU KUMIAI
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by YOYU TANSANENGATA NENRYO DENCH, YOYU TANSANENGATA NENRYO DENCHI HATSUDEN SYSTEM GIJUTSU KENKYU KUMIAI filed Critical YOYU TANSANENGATA NENRYO DENCH
Priority to JP10054360A priority Critical patent/JPH11233121A/en
Publication of JPH11233121A publication Critical patent/JPH11233121A/en
Pending legal-status Critical Current

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Classifications

    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30Hydrogen technology
    • Y02E60/50Fuel cells
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50Manufacturing or production processes characterised by the final manufactured product

Landscapes

  • Inert Electrodes (AREA)
  • Fuel Cell (AREA)
  • Powder Metallurgy (AREA)

Abstract

PROBLEM TO BE SOLVED: To effectively inhibit the elution of an air electrode material, such as nickel or iron, by forming the air electrode material from covered particles obtained when nickel or iron particles are covered with cobalt or cobalt oxide on their surfaces. SOLUTION: An air electrode material comprises covered particles excellent in molten salt resistance, which are obtained when material particles functioning as an air electrode during battery operation are covered at their surfaces. Nickel is converted into nickel oxide by oxidization process after being assembled into the battery to function as an air electrode. Iron is also converted into iron oxide and functions in the same way. The amount of cobalt or cobalt oxide added as cover material particles is preferably 2 to 30 wt.% of the total weight of the air electrode material particles. At less than 2 wt.%, it is difficult to cover the surfaces of the air electrode material particles uniformly; in excess of 30 wt.%, the amount of the cover material is so large that the material is likely to remain without covering the air electrode material.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】この発明は、溶融炭酸塩型燃
料電池の空気極に関し、特に、耐溶融塩性に優れた空気
極材料及びその製造方法に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air electrode of a molten carbonate fuel cell, and more particularly to an air electrode material excellent in molten salt resistance and a method of manufacturing the same.

【0002】[0002]

【従来の技術】溶融炭酸塩型燃料電池(以下、単に、M
CFCと略す。)は、2つの多孔質電極(燃料極と空気
極)とそれらの間に挟まれた電解質及びこれを保持して
いる電解質板によって構成されている。
2. Description of the Related Art A molten carbonate fuel cell (hereinafter simply referred to as M
Abbreviated as CFC. ) Is composed of two porous electrodes (a fuel electrode and an air electrode), an electrolyte interposed therebetween, and an electrolyte plate holding the electrolyte.

【0003】通常、燃料極(陰極)としてニッケル(N
i)を用い、空気極(陽極)としてニッケル酸化物(N
iO)を用いて、電解質としては、溶融アルカリ炭酸
塩、すなわち、炭酸リチウム、炭酸カリウム、炭酸ナト
リウム等の混合塩、一般的には炭酸リチウム62%モ
ル、炭酸カリウム38%モルのものが用いられる。
Usually, nickel (N) is used as a fuel electrode (cathode).
i) and nickel oxide (N
Using iO) as the electrolyte, a molten alkali carbonate, that is, a mixed salt of lithium carbonate, potassium carbonate, sodium carbonate, etc., generally, 62% mol of lithium carbonate and 38% mol of potassium carbonate are used. .

【0004】このようなMCFCが実用化されるために
は、40,000時間以上の寿命が必要とされているが、電解
質の損失、空気極の溶出や、セパレータの腐食等の課題
を抱えているため、その達成は難しい。現在、空気極材
料として使用されているNiOにおいては、電池運転中
に、電解質の溶融炭酸塩中に微量溶解し、さらに、この
溶解した酸化ニッケルは、溶融炭酸塩中において、式
(1)の反応によって、ニッケルイオンとして拡散す
る。 NiO+CO2 →Ni2++CO3 2-……(1) 拡散したニッケルイオンは、溶融炭酸塩中に溶解してい
る水素によって還元される。金属ニッケルは、溶融炭酸
塩にほとんど溶解しないので、電解質板中に粒子状に析
出してしまう。この結果、セルの内部短絡が発生して、
電池電圧が急激に低下し、電池としての正常な運転が不
可能となる。 したがって、空気極の溶出抑制は、最重
要課題と考えられている。
[0004] In order for such an MCFC to be put into practical use, a service life of 40,000 hours or more is required. However, there are problems such as loss of electrolyte, elution of the air electrode, and corrosion of the separator. It is difficult to achieve. At present, NiO, which is currently used as an air electrode material, is dissolved in a trace amount in the molten carbonate of the electrolyte during the operation of the battery, and the dissolved nickel oxide is dissolved in the molten carbonate by the formula (1) By the reaction, it diffuses as nickel ions. NiO + CO 2 → Ni 2+ + CO 3 2- (1) The diffused nickel ions are reduced by hydrogen dissolved in the molten carbonate. Since metallic nickel hardly dissolves in the molten carbonate, it precipitates in the form of particles in the electrolyte plate. As a result, an internal short circuit occurs in the cell,
The battery voltage drops sharply, making normal operation as a battery impossible. Therefore, suppression of elution of the air electrode is considered to be the most important issue.

【0005】[0005]

【発明が解決しようとする課題】そこで、本発明では、
従来電極と同等な電極特性を保持しつつ、耐溶融塩性に
優れる空気極を得ることのできる空気極材料及びその製
造方法を提供することをその目的とする。
Therefore, in the present invention,
An object of the present invention is to provide an air electrode material capable of obtaining an air electrode having excellent molten salt resistance while maintaining electrode characteristics equivalent to those of a conventional electrode, and a method of manufacturing the same.

【0006】[0006]

【課題を解決するための手段】本発明者らは、本質的に
空気極となりうる粉体粒子表面を、耐溶融塩性に優れる
皮膜を形成しうる材料で被覆した被覆粒子を形成し、こ
の粒子からなる粉体を空気極材料とすることにより、効
率よく電極特性と耐溶融塩性を得られることを見いだし
た。すなわち、本発明は、ニッケル粒子あるいは鉄粒子
の表面をコバルトあるいはコバルト酸化物で被覆した被
覆粒子からなることを特徴とする溶融炭酸塩型燃料電池
の空気極材料である。この空気極材料においては、電池
運転時に空気極となるニッケル粒子あるいは鉄粒子の表
面を、予め、コバルトあるいはコバルト酸化物で被覆し
た被覆粒子とされている。かかる被覆粒子からなる粉末
を成形し焼結したものは、電池運転時の酸化反応によ
り、ニッケルあるいは鉄の空気極材料の溶出を効果的に
抑制することができるとともに、電極特性も維持される
空気極となる。上記発明においては、コバルトの含有量
がニッケル粒子あるいは鉄粒子の全重量に対して2wt%
〜30wt%であることが好ましい形態である。
Means for Solving the Problems The present inventors have formed coated particles in which the surface of powder particles, which can be essentially an air electrode, is coated with a material capable of forming a film having excellent molten salt resistance. It has been found that electrode characteristics and molten salt resistance can be efficiently obtained by using a powder composed of particles as an air electrode material. That is, the present invention is an air electrode material for a molten carbonate fuel cell, comprising nickel or iron particles coated with cobalt or cobalt oxide. In this air electrode material, nickel particles or iron particles serving as an air electrode during battery operation are coated with cobalt or cobalt oxide in advance. Powder obtained by molding and sintering the powder composed of such coated particles can effectively suppress the elution of the air electrode material of nickel or iron by the oxidation reaction during battery operation, and maintain the electrode characteristics. Become a pole. In the above invention, the content of cobalt is 2% by weight based on the total weight of the nickel particles or the iron particles.
It is a preferred embodiment that the content is 3030 wt%.

【0007】また、本発明は、ニッケル粉末あるいは鉄
粉末と、コバルト粉末あるいはコバルト酸化物粉末とを
機械的に混合して、ニッケル粒子あるいは鉄粒子の表面
をコバルトあるいはコバルト酸化物で被覆した被覆粒子
からなる粉末を得る溶融炭酸塩型燃料電池の空気極材料
の製造方法である。粉末の機械的混合によってニッケル
粒子等の表面を被覆することにより、皮膜の厚みや被覆
量をコントロールすることが容易となる。
Further, the present invention provides a coated particle obtained by mechanically mixing a nickel powder or an iron powder with a cobalt powder or a cobalt oxide powder, and coating the surface of the nickel or iron particles with cobalt or cobalt oxide. This is a method for producing an air electrode material of a molten carbonate fuel cell for obtaining a powder comprising: By coating the surface of nickel particles or the like by mechanical mixing of the powder, it becomes easy to control the thickness and coating amount of the coating.

【0008】また、本発明は、ニッケル粒子あるいは鉄
粒子の表面をコバルトあるいはコバルト酸化物で被覆し
た被覆粒子からなる空気極材料を用いて形成した溶融炭
酸塩型燃料電池の空気極である。
Further, the present invention is an air electrode of a molten carbonate type fuel cell formed by using an air electrode material comprising coated particles in which nickel particles or iron particles are coated with cobalt or cobalt oxide.

【0009】[0009]

【発明の実施の形態】本発明の空気極材料は、電池運転
時において空気極としての機能を果たしうる材料粒子の
表面に耐溶融塩性に優れる被覆材料を付与した被覆粒子
からなる。空気極材料粒子としては、ニッケル粒子かあ
るいは鉄粒子が好ましい。ニッケルは、電池組み込み後
における酸化等による酸化処理によりニッケル酸化物と
なり、空気極として機能する。鉄は、同じく酸化処理に
より鉄酸化物となり空気極として機能する。
BEST MODE FOR CARRYING OUT THE INVENTION The air electrode material of the present invention comprises coated particles obtained by adding a coating material having excellent molten salt resistance to the surface of a material particle capable of functioning as an air electrode during battery operation. As the cathode material particles, nickel particles or iron particles are preferable. Nickel becomes nickel oxide by an oxidation treatment such as oxidation after the battery is incorporated, and functions as an air electrode. Iron also becomes iron oxide by the oxidation treatment and functions as an air electrode.

【0010】空気極材料粒子を被覆する被覆材料として
は、電池運転時において耐溶融塩性に優れるとともに導
電性を有するLiCoO2 を形成しうるコバルト(C
o)あるいはCo酸化物が好ましい。コバルトあるいは
コバルト酸化物の添加量は、空気極材料粒子の全重量に
対してコバルトとして2wt%〜30wt%であることが好
ましい。2wt%未満であると、均一に空気極材料粒子の
表面を被覆することが困難になるからであり、30wt%
を越えると被覆材料が多すぎて空気極材料を被覆するこ
となく残留しやすくなるからである。より好ましくは、
5wt%から20wt%である。かかる範囲で被覆材料が多
いほど、より厚く、より均一に被覆構造が形成されるこ
とがわかっている。かかる被覆構造によれば、耐食性、
寿命とも向上される。
As a coating material for coating the air electrode material particles, cobalt (C) which can form LiCoO 2 having excellent molten salt resistance and conductivity during battery operation is used.
o) or Co oxide is preferred. The addition amount of cobalt or cobalt oxide is preferably 2% by weight to 30% by weight as cobalt with respect to the total weight of the air electrode material particles. If the content is less than 2 wt%, it becomes difficult to uniformly coat the surface of the air electrode material particles,
This is because if it exceeds, the coating material is too much and tends to remain without coating the air electrode material. More preferably,
5 wt% to 20 wt%. It has been found that the more coating material in such a range, the thicker and more uniformly the coating structure is formed. According to such a coating structure, corrosion resistance,
The service life is also improved.

【0011】この被覆材料たるCoあるいはCo酸化物
に、マグネシウム(Mg)、マグネシウム酸化物、ある
いはマグネシウム塩がさらに添加されていてもよい。M
gが添加されていると、被覆材料が電池運転時におい
て、Mg−LiCoO2 あるいは、Mg−Li(Co、
Ni)O2 (空気極材料がニッケルの場合、ニッケル粒
子表面での固溶化によって形成される)を構成して、優
れた導電率を発揮するからである。この場合、Mgの添
加量は、Coのモル量に対して、0.2モル以下である
ことが好ましい。Mgが0.2モルを越えると、被覆材
料の導電率が低下するからである。より好ましくは、C
oのモル量に対して0.1以下である。なお、Li2
3 等のリチウム(Li)塩がさらに添加されていても
よい。リチウムは、電解質内にリチウムイオンがあるの
で、特に添加する必要がないが、リチウムイオンを添加
しておくことにより、電解質組成におけるリチウムイオ
ンのバランスをくずすことなくコバルトや鉄をリチウム
化できるというメリットもある。
[0011] To the coating material Co or Co oxide, magnesium (Mg), magnesium oxide or magnesium salt may be further added. M
When g is added, the coating material during cell operation, Mg-LiCoO 2 or, Mg-Li (Co,
This is because Ni) O 2 (formed by solid solution on the surface of nickel particles when the air electrode material is nickel) constitutes an excellent electrical conductivity. In this case, the added amount of Mg is preferably 0.2 mol or less based on the molar amount of Co. This is because when the content of Mg exceeds 0.2 mol, the conductivity of the coating material decreases. More preferably, C
It is 0.1 or less with respect to the molar amount of o. Note that Li 2 C
A lithium (Li) salt such as O 3 may be further added. Since lithium contains lithium ions in the electrolyte, there is no particular need to add lithium. However, the advantage of adding lithium ions is that cobalt and iron can be lithiated without breaking the balance of lithium ions in the electrolyte composition. There is also.

【0012】空気極材料粒子表面に被覆材料を被覆する
には、粉末と粉末との機械的混合方法や、沈殿法、含浸
法等を初めとする各種コーティング法、皮膜形成法によ
り可能である。特に機械的混合方法によると、多くの被
覆材料を空気極材料粒子表面に付着させることができる
ため好ましい。機械的混合方法としては、ハイブリダー
ゼーションシステム(奈良機械製作所)、コスモス(川
崎重工業)、メカノフージョンシステム(ホソカワミク
ロン)、メカノミル(岡田精工)、シータ・コンポーザ
(徳寿工作所)等の粒子複合化装置を用いた混合方法を
使用することが好ましい。被覆型複合粒子の作製技術を
含む機械的な粒子複合化技術については、内藤牧男、機
械的粒子複合化技術の現状と展望(粉体と工業(vol.2
5、NO. 5(1994)、第31頁〜42頁)に詳細に記載され
ている。
The surface of the cathode material particles can be coated with a coating material by a mechanical mixing method of the powder, a precipitation method, an impregnation method and other various coating methods, and a film forming method. In particular, the mechanical mixing method is preferable because many coating materials can be attached to the surface of the air electrode material particles. As the mechanical mixing method, a particle complexing device such as a hybridization system (Nara Machinery), a cosmos (Kawasaki Heavy Industries), a mechanofusion system (Hosokawa Micron), a mechanomill (Okada Seiko), theta composer (Tokuju Works), etc. It is preferable to use a mixing method using For the mechanical particle composite technology including the production technology of coated composite particles, Makoto Naito, Current Status and Prospect of Mechanical Particle Composite Technology (Powder and Industry (vol.2
5, No. 5 (1994), pp. 31-42).

【0013】このような被覆粒子から形成される粉末
は、MCFCの空気極材料として好ましいものである。
この空気極材料粉末を成形し、還元雰囲気中で焼成し、
この焼成体をMCFCに組み込んでin-situ 酸化により
空気極を形成した。この結果、空気極材料粒子は、ニッ
ケル酸化物あるいは鉄酸化物となり、被覆材料は、Li
CoO2あるいはMg- LiCoO2 、さらには空気極
材料粒子と一部固溶したLi(Co、Ni)O2 等とな
る。なお、空気極であるニッケル酸化物は、一部リチウ
ム化され、鉄酸化物は、ほぼリチウム化されることが知
られている。
The powder formed from such coated particles is preferable as an air electrode material for MCFC.
This air electrode material powder is molded and fired in a reducing atmosphere,
The fired body was incorporated into an MCFC to form an air electrode by in-situ oxidation. As a result, the air electrode material particles become nickel oxide or iron oxide, and the coating material is Li
CoO2 or Mg- LiCoO 2, further comprising a part and the air electrode material particles dissolved was Li (Co, Ni) O 2 and the like. It is known that nickel oxide as an air electrode is partially lithiated, and iron oxide is almost lithiated.

【0014】最終的に電池運転状態で得られる空気極と
して、以下の組み合わせが例示される。 空気極材料粒子 被覆材料 ニッケル酸化物 LiCoO2 及び/又はLi(Co,Ni)O2 ニッケル酸化物 Mg−LiCoO2 及び/又は Mg−Li(Co,Ni)O2 鉄酸化物 LiCoO2 及び/又はLi(Co,Fe)O2 鉄酸化物 Mg−LiCoO2 及び/又は Mg−Li(Co,Fe)O2 さらに、これらの空気極材料粒子同士を組み合わせるこ
とも可能である。その場合には、組み合わせた空気極材
料に対応して、被覆材料との固溶体が空気極材料粒子表
面において形成されることになる。
The following combinations are exemplified as the air electrode finally obtained in the battery operating state. Air electrode material particle coating material nickel oxide LiCoO 2 and / or Li (Co, Ni) O 2 nickel oxide Mg-LiCoO 2 and / or Mg-Li (Co, Ni) O 2 iron oxide LiCoO 2 and / or Li (Co, Fe) O 2 iron oxide Mg-LiCoO 2 and / or Mg-Li (Co, Fe) O 2 addition, it is also possible to combine these air electrode material particles with each other. In that case, a solid solution with the coating material is formed on the surface of the cathode material particles corresponding to the combined cathode material.

【0015】本発明の空気極材料粉末は、空気極材料粒
子が、予め、耐溶融塩性に優れて導電性を有しうる被覆
材料で被覆した被覆粒子となっているので、この被覆粒
子からなる粉末を成形、焼成、酸化して得られる空気極
は、個々の空気極材料粒子が耐溶融塩性に優れた特性を
保有したものとなっている。したがって、安定して、耐
溶融塩性を発揮できて、MCFCの長期運転に寄与する
ことができる。また、空気極材料粒子の表面をCoによ
り被覆してLiCoO2 により耐溶融塩性を付与するの
で、高価なCoを多く使用しなくても、効率的に耐溶融
塩性を付与することができるものとなっている。また、
個々の粒子の表面をCoにより被覆するので、電池運転
時には、LiCoO2 の耐溶融塩性が無駄なく発揮され
る。
In the cathode material powder of the present invention, the cathode material particles are coated particles which are previously coated with a coating material which is excellent in molten salt resistance and can be conductive. The air electrode obtained by molding, sintering and oxidizing the resulting powder has individual air electrode material particles possessing excellent properties of molten salt resistance. Therefore, the molten salt resistance can be exhibited stably and can contribute to the long-term operation of the MCFC. In addition, since the surface of the air electrode material particles is coated with Co to provide the molten salt resistance with LiCoO 2 , the molten salt resistance can be efficiently provided without using a large amount of expensive Co. It has become something. Also,
Since the surface of each particle is coated with Co, the molten salt resistance of LiCoO 2 is exhibited without waste during battery operation.

【0016】[0016]

【実施例】以下、本発明を実施例を挙げて具体的に説明
する。 (実施例1)空気極材料粒子をニッケル粒子(平均粒
径:7μm)とし、被覆材料を酸化コバルト(CoO)
(平均粒径:0.2μm)として、ホソカワミクロン社
製のメカノフージョンシステム(AM−20FVS)
で、1000rpm、30分間の条件で混合して被覆粒
子を得た。なお、ニッケル粒子の全重量に対して、酸化
コバルトをコバルトとして5wt%となるように添加して
混合したもの(以下、5wt%被覆粒子粉末という。)
と、酸化コバルトをコバルトとして10wt%となるよう
に添加して混合したもの(以下、10wt%被覆粒子粉末
という。)の2種の被覆粒子粉末を得た。図1に、混合
前のニッケル粒子の電子顕微鏡写真を示し、図2に、混
合前の酸化コバルトの電子顕微鏡写真を示す。また、図
3には、本実施例の混合により得られた5wt%被覆粒子
の電子顕微鏡写真(図3(a)は3000倍、図3
(b)は10000倍)を示す。これらの電子顕微鏡写
真から、ニッケル粒子は、酸化コバルト粒子にてほぼ均
一に被覆されていることがわかった。
EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples. (Example 1) The cathode material particles were nickel particles (average particle size: 7 µm), and the coating material was cobalt oxide (CoO).
(Average particle size: 0.2 μm) as a mechanofusion system (AM-20FVS) manufactured by Hosokawa Micron Corporation
At 1000 rpm for 30 minutes to obtain coated particles. Here, cobalt oxide is added and mixed so as to be 5 wt% as cobalt with respect to the total weight of the nickel particles (hereinafter referred to as 5 wt% coated particle powder).
And 10% by weight of cobalt oxide added and mixed (hereinafter referred to as 10% by weight coated particle powder) to obtain two types of coated particle powder. FIG. 1 shows an electron micrograph of nickel particles before mixing, and FIG. 2 shows an electron micrograph of cobalt oxide before mixing. FIG. 3 shows an electron micrograph of the 5 wt% coated particles obtained by mixing in this example (FIG.
(B) is 10,000 times). From these electron micrographs, it was found that the nickel particles were almost uniformly coated with the cobalt oxide particles.

【0017】(実施例2)次に、実施例1で得られた2
種の被覆粒子からなる粉体をそれぞれ所定の形状に成形
し、850℃、5時間で焼成して焼結体(電極)を得
た。5wt%被覆粒子粉末から形成した電極の表面の電子
顕微鏡写真(図4(a)は4000倍、図4(b)は1
0000倍)を示す。図4の写真によれば、電極の表面
は、酸化コバルトによって被覆されたニッケル粒子の形
状がそのまま観察されるとともに、ニッケル粒子を被覆
する酸化コバルトの形態が維持され、焼結によってでき
た凹凸形状を示していた。
(Embodiment 2) Next, the 2
Each of the powders composed of the seed coated particles was formed into a predetermined shape and fired at 850 ° C. for 5 hours to obtain a sintered body (electrode). Electron micrographs of the surface of the electrode formed from the 5 wt% coated particle powder (FIG. 4A is 4000 times, FIG. 4B is 1 ×)
0000 times). According to the photograph of FIG. 4, the shape of the nickel particles coated with cobalt oxide is observed as it is on the surface of the electrode, and the shape of the cobalt oxide coating the nickel particles is maintained, and the uneven shape formed by sintering is obtained. Was shown.

【0018】(実施例3)実施例2で得た電極を用い
て、溶融炭酸塩(リチウム塩62mol %、カリウム塩3
8mol %)中での溶出試験を実施した。試験は、完全浸
漬溶出試験とし、圧力1atm 、雰囲気(70%air/30
%CO2 、 バブリング)のもと、300℃/hで昇温し、6
50℃で200時間保持し、所定時間において1gを採
取し、ICP発光分析により溶融炭酸塩中のニッケル、
コバルトを定量した。なお、比較のために、ニッケル酸
化物(NiO)、LiCoO2 についても溶出試験を行
った。5wt%被覆粒子粉末由来の電極についての結果を
図5に示す。5wt%被覆粒子粉末由来の電極について
は、被覆されないニッケル酸化物に比較して、ニッケル
溶出量が約1/2に低減された。また、コバルトの溶出
は確認されなかった。10wt%被覆粒子粉末由来の電極
については、被覆されないものに比較してニッケル溶出
量は約1/3に低減された。
Example 3 Using the electrode obtained in Example 2, molten carbonate (lithium salt 62 mol%, potassium salt 3
(8 mol%). The test was a complete immersion dissolution test, with a pressure of 1 atm and an atmosphere (70% air / 30
% CO 2, bubbling), and the temperature was raised at 300 ° C / h.
It is kept at 50 ° C. for 200 hours, and 1 g is sampled at a predetermined time.
Cobalt was quantified. For comparison, a dissolution test was also performed on nickel oxide (NiO) and LiCoO 2 . FIG. 5 shows the results for the electrode derived from the 5 wt% coated particle powder. For the electrode derived from the 5 wt% coated particle powder, the amount of nickel eluted was reduced to about 比較 as compared to the uncoated nickel oxide. Also, no elution of cobalt was confirmed. For the electrode derived from the 10 wt% coated particle powder, the amount of nickel eluted was reduced to about 1/3 as compared with the electrode not coated.

【0019】(実施例4)実施例1で作製した5wt%被
覆粒子粉末200g、バインダー20g、可塑剤20g
混合して、得られたスラリーをドクターブレード装置に
よりテープ状に成形した。これを、800℃、Ar−H
2 雰囲気中で、2時間焼成して電極を作製し、MCFC
に組み込んで電池試験を実施した。電極は、MCFCの
セルに組み込み後、650℃、カソードガス雰囲気下で
in-situ 酸化され、空気極となった。150mA/cm
2 の電流密度でのこの空気極の分極値は、約60mVで
あり、従来の電極(NiO)と同等であった。
Example 4 200 g of the 5 wt% coated particle powder prepared in Example 1, 20 g of a binder and 20 g of a plasticizer
After mixing, the obtained slurry was formed into a tape shape by a doctor blade device. This is heated at 800 ° C. and Ar-H
Baking in 2 atmospheres for 2 hours to produce electrodes, MCFC
And a battery test was conducted. The electrodes are assembled in a MCFC cell at 650 ° C under a cathode gas atmosphere.
Oxidized in-situ to form an air electrode. 150mA / cm
The polarization value of this cathode at a current density of 2 was about 60 mV, which was equivalent to a conventional electrode (NiO).

【0020】[0020]

【発明の効果】本発明によると、従来電極と同等な電極
特性を保持しつつ、耐溶融塩性に優れる空気極を得るこ
とのできる空気極材料を得ることができる。
According to the present invention, it is possible to obtain an air electrode material capable of obtaining an air electrode having excellent molten salt resistance while maintaining electrode characteristics equivalent to those of a conventional electrode.

【図面の簡単な説明】[Brief description of the drawings]

【図1】混合前のニッケル粒子の電子顕微鏡写真を示す
図である。
FIG. 1 is a view showing an electron micrograph of nickel particles before mixing.

【図2】混合前の酸化コバルトの電子顕微鏡写真を示す
図である。
FIG. 2 is a view showing an electron micrograph of cobalt oxide before mixing.

【図3】5wt%被覆粒子粉末の電子顕微鏡写真((a)
は3000倍、図3(b)は10000倍)を示す図で
ある。
FIG. 3 is an electron micrograph of 5 wt% coated particle powder ((a))
3 is 3000 times and FIG. 3B is 10000 times.

【図4】5wt%被覆粒子粉末から形成した電極の表面の
電子顕微鏡写真((a)は4000倍、(b)は100
00倍)を示す図である。
FIG. 4 is an electron micrograph of the surface of an electrode formed from 5 wt% coated particle powder ((a) is 4000 times, (b) is 100 times).
FIG.

【図5】溶出試験結果を示す図である。FIG. 5 is a diagram showing a dissolution test result.

フロントページの続き (72)発明者 内藤 牧男 愛知県名古屋市熱田区六野二丁目4番1号 財団法人ファインセラミックスセンター 内 (72)発明者 堀田 禎 愛知県名古屋市熱田区六野二丁目4番1号 財団法人ファインセラミックスセンター 内(72) Inventor Makio Naito 2-4-1 Rokuno, Atsuta-ku, Nagoya City, Aichi Prefecture Inside the Fine Ceramics Center (72) Inventor Tadashi Hotta 2-4-2, Rokuno, Atsuta-ku, Nagoya City, Aichi Prefecture No. 1 Inside the Fine Ceramics Center

Claims (4)

【特許請求の範囲】[Claims] 【請求項1】ニッケル粒子あるいは鉄粒子の表面をコバ
ルトあるいはコバルト酸化物で被覆した被覆粒子からな
ることを特徴とする溶融炭酸塩型燃料電池の空気極材
料。
An air electrode material for a molten carbonate fuel cell comprising nickel or iron particles coated with cobalt or cobalt oxide.
【請求項2】コバルトの含有量がニッケル粒子あるいは
鉄粒子の全重量に対して2wt%〜30wt%であることを
特徴とする請求項1記載の空気極材。
2. The air electrode material according to claim 1, wherein the content of cobalt is 2% by weight to 30% by weight based on the total weight of the nickel particles or the iron particles.
【請求項3】ニッケル粉末あるいは鉄粉末と、コバルト
粉末あるいはコバルト酸化物粉末とを混合して、ニッケ
ル粒子あるいは鉄粒子の表面をコバルトあるいはコバル
ト酸化物で被覆した被覆粒子からなる粉末を得る溶融炭
酸塩型燃料電池の空気極材料の製造方法。
3. A molten carbonate obtained by mixing a nickel powder or an iron powder with a cobalt powder or a cobalt oxide powder to obtain a powder comprising nickel or iron particles whose surfaces are coated with cobalt or cobalt oxide. A method for producing a cathode material for a salt fuel cell.
【請求項4】ニッケル粒子あるいは鉄粒子の表面をコバ
ルトあるいはコバルト酸化物で被覆した被覆粒子からな
る空気極材料を用いて形成した溶融炭酸塩型燃料電池の
空気極。
4. An air electrode of a molten carbonate fuel cell formed by using an air electrode material made of coated particles in which the surface of nickel particles or iron particles is coated with cobalt or cobalt oxide.
JP10054360A 1998-02-18 1998-02-18 Air electrode material for molten carbonate fuel cell and its manufacture Pending JPH11233121A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10054360A JPH11233121A (en) 1998-02-18 1998-02-18 Air electrode material for molten carbonate fuel cell and its manufacture

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10054360A JPH11233121A (en) 1998-02-18 1998-02-18 Air electrode material for molten carbonate fuel cell and its manufacture

Publications (1)

Publication Number Publication Date
JPH11233121A true JPH11233121A (en) 1999-08-27

Family

ID=12968486

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10054360A Pending JPH11233121A (en) 1998-02-18 1998-02-18 Air electrode material for molten carbonate fuel cell and its manufacture

Country Status (1)

Country Link
JP (1) JPH11233121A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1839351A2 (en) * 2004-12-09 2007-10-03 Praxair Technology, Inc. Manufacturing method and current collector
JP2008503058A (en) * 2004-06-15 2008-01-31 フュエルセル エナジー, インコーポレイテッド Hardware on the cathode side of carbonate fuel cell
JP5830010B2 (en) * 2010-03-17 2015-12-09 新日鉄住金化学株式会社 Method for producing nickel-cobalt nanoparticles

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008503058A (en) * 2004-06-15 2008-01-31 フュエルセル エナジー, インコーポレイテッド Hardware on the cathode side of carbonate fuel cell
EP1839351A2 (en) * 2004-12-09 2007-10-03 Praxair Technology, Inc. Manufacturing method and current collector
EP1839351A4 (en) * 2004-12-09 2013-01-09 Praxair Technology Inc Manufacturing method and current collector
JP5830010B2 (en) * 2010-03-17 2015-12-09 新日鉄住金化学株式会社 Method for producing nickel-cobalt nanoparticles

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