JPH06116016A - Production of beta-alumina electrolyte - Google Patents
Production of beta-alumina electrolyteInfo
- Publication number
- JPH06116016A JPH06116016A JP4227814A JP22781492A JPH06116016A JP H06116016 A JPH06116016 A JP H06116016A JP 4227814 A JP4227814 A JP 4227814A JP 22781492 A JP22781492 A JP 22781492A JP H06116016 A JPH06116016 A JP H06116016A
- Authority
- JP
- Japan
- Prior art keywords
- alumina
- beta
- sodium
- lithium
- powder
- 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.)
- Granted
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/36—Accumulators not provided for in groups H01M10/05-H01M10/34
- H01M10/39—Accumulators not provided for in groups H01M10/05-H01M10/34 working at high temperature
- H01M10/3909—Sodium-sulfur cells
- H01M10/3918—Sodium-sulfur cells characterised by the electrolyte
-
- 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
- Y02E60/10—Energy storage using batteries
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Compositions Of Oxide Ceramics (AREA)
- Secondary Cells (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明はナトリウムイオンをキャ
リアとして作動するナトリウム−イオウ電池及びナトリ
ウム−溶融塩電池等の二次電池あるいはアルカリ金属熱
電変換電池等の固体電解質として用いるベータアルミナ
の製造法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing beta-alumina used as a solid electrolyte for secondary batteries such as sodium-sulfur batteries and sodium-molten salt batteries which operate with sodium ion as a carrier, or for alkali metal thermoelectric conversion batteries. .
【０００２】[0002]
【従来の技術】ベータアルミナ電解質は高いナトリウム
イオン導電性を有するために、ナトリウムイオンをキャ
リアとする各種電池の電解質として利用されている。そ
してこの電池は電池の内部抵抗のかなりの部分を占める
ため、低抵抗でかつ高強度を示す緻密焼結体が望まし
く、また焼結を行う高温時、例えば１７００℃で揮発し
やすいナトリウムを含有するために、なるべく低温で焼
結する方が望ましい。またベータアルミナにはβ−アル
ミナ（理論組成Ｎａ2 Ｏ・１１Ａｌ2 Ｏ3 ）及びβ″−
アルミナ（理論組成Ｎａ2 Ｏ・５．３Ａｌ2 Ｏ3 ）とい
う２種類の結晶形が存在し、β″−アルミナの方が導電
性が高く電池として高性能を示すため、実用的にはβ″
−アルミナあるいはβ″−アルミナとβ−アルミナの混
合物のものが多用されている。2. Description of the Related Art Beta-alumina electrolytes are used as electrolytes for various batteries using sodium ions as carriers because they have high sodium ion conductivity. Since this battery occupies a large part of the internal resistance of the battery, a dense sintered body having low resistance and high strength is desirable, and it also contains sodium which easily volatilizes at a high temperature for sintering, for example, 1700 ° C. Therefore, it is desirable to sinter at a temperature as low as possible. Beta-alumina includes β-alumina (theoretical composition Na 2 O · 11Al 2 O 3 ) and β ″-
There are two types of crystal form called alumina (theoretical composition Na 2 O.5.3Al 2 O 3 ), and β ″ -alumina has higher conductivity and higher performance as a battery, so β ″ is practically used.
Alumina or a mixture of β ″ -alumina and β-alumina is often used.
【０００３】従来のベータアルミナの製造法は特公昭５
７−１５０６３号公報にみられるように、アルミナと炭
酸ナトリウムを混合後焼成して得たβ−アルミナとβ″
−アルミナの混合物の仮焼粉と、アルミナと炭酸リチウ
ムを混合後焼成して得たゼータアルミナ（理論組成Ｌｉ
2 Ｏ・Ａｌ2 Ｏ3 ）の結晶相を示す仮焼粉を再度混合
し、成型して焼結後にβ″−アルミナを得るという方法
である。この方法は混合前の仮焼粉にゼータアルミナを
用いることからゼータプロセスとよばれている。A conventional method for producing beta-alumina is Japanese Patent Publication No.
7-15063, β-alumina and β ″ obtained by mixing alumina and sodium carbonate and then firing.
-A calcined powder of a mixture of alumina and zeta-alumina (theoretical composition Li
2 O · Al 2 O 3) were mixed calcined powder showing the crystal phase again, molded to after sintering beta "-. A method of obtaining alumina The method zeta alumina calcined powder before mixing It is called the Zeta process because it uses.
【０００４】さらに、上記公報の中にはナトリウムとリ
チウムの水溶性塩（例えば硝酸塩、硫酸塩、塩化物等）
の溶液とアルミナ粉体のスラリを混合後、乾燥・仮焼し
て、その後β″−アルミナ焼結体をえる方法が記載され
ている。しかしながら、この方法については詳細な実施
例は全く示されておらず、良好な電解質が得られるかど
うかは明かではない。Further, in the above publication, water-soluble salts of sodium and lithium (for example, nitrates, sulfates, chlorides, etc.)
The method of mixing the solution of (1) and the slurry of alumina powder, and then drying and calcination to obtain a β ″ -alumina sintered body is described. However, a detailed example of this method is not shown at all. No, it is not clear whether a good electrolyte will be obtained.
【０００５】また、特公昭５５−９０４７０号公報に
は、非水溶媒に可溶なアルミニウム、ナトリウム及びリ
チウムのアルコキシドを加水分解後に乾燥・仮焼操作を
行い、焼成してベータアルミナを得る方法が記載されて
いる。Japanese Patent Publication No. 55-90470 discloses a method of obtaining beta-alumina by hydrolyzing aluminum, sodium and lithium alkoxides soluble in a non-aqueous solvent, followed by drying and calcination, followed by firing. Have been described.
【０００６】さらに、公知の方法であるが、アルミニウ
ム、ナトリウム及びリチウムの３種の粉末原料を同時に
乾式あるいは湿式で混合後、仮焼してベータアルミナを
得る方法がある。Further, as a known method, there is a method in which three kinds of powder raw materials of aluminum, sodium and lithium are simultaneously mixed in a dry or wet manner and then calcined to obtain beta alumina.
【０００７】また、本発明者等は先に非水溶媒に、アル
ミニウムの出発原料粉末、ナトリウムの出発原料粉末
と、一部あるいは全量を上記非水溶媒に溶解する有機リ
チウム化合物としたリチウムの出発原料とを混合してス
ラリを調製し、該スラリの乾燥粉または仮焼粉を成型
後、焼結するという簡便な方法において、アルミナ原料
の一次粒子径を制御することで従来法と同等以上の導電
性及び強度を示すベータアルミナの電解質の製造方法を
提案した。（平成４年７月６日付「ベータアルミナ電解
質の製造方法」として特許出願）The inventors of the present invention have previously prepared a starting material powder of aluminum and a starting material powder of sodium in a non-aqueous solvent, and starting lithium of an organolithium compound in which a part or all of the starting material powder is dissolved in the non-aqueous solvent. In a simple method of mixing the raw material to prepare a slurry, molding the dried powder or calcined powder of the slurry, and then sintering, it is possible to control the primary particle diameter of the alumina raw material to be equal to or more than the conventional method. A method for producing beta-alumina electrolyte that exhibits conductivity and strength was proposed. (Patent application as "Beta-Alumina Electrolyte Manufacturing Method" dated July 6, 1992)
【０００８】最後に、本発明者等はこれまた先に非水溶
媒に、アルミニウムの出発原料粉末、ナトリウムの出発
原料粉末と、一部あるいは全量を上記非水溶媒に溶解す
る有機リチウム化合物としたリチウムの出発原料とを混
合してスラリを調製し、該スラリの乾燥粉を仮焼した
後、粉砕・成型後、焼結するという簡便な方法において
特性に及ぼすアルミナ原料の影響を低減させ、従来法と
同等以上の特性を示すベータアルミナの電解質を再現性
よく製造する方法を提案した。（特願平４−２０７６１
０）Finally, the inventors of the present invention also previously prepared aluminum starting material powder, sodium starting material powder, and a part or all of the organolithium compound dissolved in the nonaqueous solvent in the nonaqueous solvent. A simple method of preparing a slurry by mixing with a lithium starting material, calcining the dried powder of the slurry, crushing and molding, and then sintering, reduces the influence of the alumina raw material on the characteristics, We proposed a method for producing a beta-alumina electrolyte that exhibits characteristics equal to or higher than those of the method with good reproducibility. (Japanese Patent Application No. 4-20761
0)
【０００９】[0009]
【発明が解決しようとする課題】上記特公昭５７−１５
０６３号公報の最も一般的な従来法では、製品における
酸化リチウムの量が０．７５重量％と非常に少ないため
に、ゼータアルミナというリチウムがアルミナ中に分散
した仮焼粉を用いて最終的にβ″−アルミナ中に分散さ
せようとするものである。該従来法のゼータプロセスで
は２種類の仮焼粉を調製後、粉砕・混合して焼結を行う
ため、混合工程が３回及び仮焼工程が２回と工程が複雑
となり製品のコストアップをもたらす。また、この方法
では、すべてが固相反応によりリチウムの拡散を行うこ
とからリチウムの不均一な分布が生じ、そこを起点に異
常粒成長が起きやすいという問題がある。[Problems to be Solved by the Invention] Japanese Patent Publication No. 57-15
In the most general conventional method disclosed in Japanese Patent No. 063, since the amount of lithium oxide in the product is very small, 0.75% by weight, zeta-alumina is used as a final product by using a calcined powder in which lithium is dispersed in alumina. It is intended to disperse in β ″ -alumina. In the conventional zeta process, two types of calcined powders are prepared, and then pulverized and mixed for sintering, so that the mixing process is performed three times and temporarily. Since the baking process is complicated because the baking process is performed twice and the cost of the product is increased, in this method, lithium is non-uniformly distributed due to the solid-state reaction, which causes an abnormal distribution of lithium. There is a problem that grain growth easily occurs.
【００１０】さらに、上記公報に記載してある水溶性の
塩を用いる方法では、上記ゼータプロセスよりもコスト
的に安価であるが、仮焼する際に特にナトリウムの水溶
性塩の量が多いため、有害なガス｛例えば窒素酸化物
（ＮＯｘ）あるいは硫黄酸化物（ＳＯｘ）｝が発生する
ばかりでなく、仮焼あるいは焼結の温度でも不揮発な塩
（塩化物等）を生成する可能性がある。また、該公報で
は具体的実施例が記載されていないため、本発明者等が
追試を行った結果、水溶性の塩を用いる方法では異常粒
成長が激しく（１００μｍ以上）、導電性の面を除き、
電池に供する電解質としての強度及び耐久性に関して非
常に劣るものであることを確認した。Further, the method using the water-soluble salt described in the above publication is cheaper in cost than the zeta process, but since the amount of the water-soluble salt of sodium is particularly large during calcination. , Not only harmful gases (for example, nitrogen oxides (NOx) or sulfur oxides (SOx)) are generated, but also non-volatile salts (chlorides, etc.) may be generated even at the temperature of calcination or sintering. . Further, since specific examples are not described in this publication, as a result of additional tests by the present inventors, the method using a water-soluble salt causes abnormal grain growth (100 μm or more) and a conductive surface Except
It was confirmed that the strength and durability of the electrolyte used in the battery were extremely poor.
【００１１】また、特公昭５５−９０４７０号公報の３
成分の原料に可溶性のアルコキシドを用いる方法では、
先ず原料のコストがかなり高くなる。また３成分を溶解
させるため、溶液中の成分は１０重量％程度であり、通
常の粉体を使用するスラリが６０から９０重量％である
ことから判断し、溶媒を含めた原料の歩留まりが悪い。
さらに、この方法は加水分解速度がかなり遅いために、
長い熟成時間を必要とするという問題がある。Further, Japanese Patent Publication No. 55-90470, No. 3,
In the method of using a soluble alkoxide as a raw material of the component,
First, the cost of raw materials is considerably high. Further, since the three components are dissolved, the content of the components in the solution is about 10% by weight, and it is judged from the fact that the slurry using ordinary powder is 60 to 90% by weight, and the yield of raw materials including the solvent is poor. .
In addition, this method has a fairly slow hydrolysis rate,
There is a problem that it requires a long aging time.
【００１２】さらに、３成分に粉体の原料を用いる公知
の方法では、前述のゼータプロセスで述べたように、リ
チウムの固相反応による分散が悪く、ベータアルミナで
はない結晶相が残るあるいは異常粒成長という問題が生
じる。Furthermore, in the known method using powder raw materials for the three components, as described in the zeta process, the dispersion due to the solid-state reaction of lithium is poor, and a crystalline phase other than beta-alumina remains or abnormal grains are present. The problem of growth arises.
【００１３】また、本発明者等が先に提案した方法に
は、簡便な方法にて従来法と同等以上の導電性及び強度
を示すベータアルミナの電解質の製造方法について提案
してあるが、アルミナ原料の一次粒子径及びそれに対す
る焼結条件の適正化をしなければ、従来法の特性を越え
ず、アルミナ原料の選択の自由度及び製品の特性の再現
性等に問題があった。In addition, in the method previously proposed by the present inventors, a method for producing an electrolyte of beta-alumina showing conductivity and strength equal to or higher than the conventional method by a simple method is proposed. If the primary particle diameter of the raw material and the sintering conditions for it are not optimized, the characteristics of the conventional method are not exceeded, and there are problems in the degree of freedom in selecting the alumina raw material and the reproducibility of the product characteristics.
【００１４】また、本発明者等の先に提案した方法（特
願平４−２０７６１０）には非水溶媒に、アルミナの出
発原料粉末、ナトリウムの出発原料粉末と、一部あるい
は全量を上記非水溶媒に溶解する有機リチウム化合物と
したリチウムの出発原料とを混合してスラリを調製し、
該スラリの乾燥粉を仮焼した後、粉砕・成型後、焼結す
るという簡便な方法において、特性に及ぼすアルミニウ
ム原料の影響を低減させ、従来法と同等以上の特性を示
すベータアルミナの電解質を再現性よく製造する方法を
提案した。しかしながら、仮焼粉のβ″−アルミナの割
合（以下β″化率と略す）が４０〜７０％であり、従来
法であるゼータ法のアルミナと炭酸ナトリウムを混合後
焼成して得たβ−アルミナとβ″−アルミナの混合物の
仮焼粉のβ″化率が約９０％であるのに比較して低い値
を示す。該方法によれば、仮焼粉を粉砕・成型後、焼結
することによりそのβ″化率はほぼ１００％になること
を示したが、仮焼粉の状態でもそのβ″化率は高い方が
よいことは明かである。アルミナとリチウムの反応性が
アルミナとナトリウムの反応性より高いために、仮焼粉
の状態でＡｌ2 Ｏ3 −Ｌｉ2 Ｏ系複合酸化物がＡｌ2 Ｏ
3 −Ｎａ2 Ｏ系複合酸化物（β″−アルミナ及びβ−ア
ルミナ）よりも先に生成し、ナトリウムのアルミナ中の
拡散を遅くしているものと思われる。このことはミクロ
な状態でのリチウムの分布に悪影響を及ぼす可能性があ
る。Further, in the method previously proposed by the present inventors (Japanese Patent Application No. 4-207610), a starting material powder of alumina and a starting material powder of sodium, and a part or all of the above-mentioned non-aqueous solvent are used. A slurry is prepared by mixing a starting material of lithium, which is an organic lithium compound dissolved in a water solvent,
A simple method of calcination of the dried powder of the slurry, crushing / molding, and sintering is used to reduce the influence of the aluminum raw material on the characteristics, and a beta-alumina electrolyte exhibiting characteristics equal to or higher than those of the conventional method is obtained. A method of manufacturing with good reproducibility was proposed. However, the proportion of β ″ -alumina in the calcined powder (hereinafter, abbreviated as β ″ conversion rate) is 40 to 70%, and β-obtained by mixing and calcining alumina and sodium carbonate of the conventional zeta method. The β ″ conversion rate of the calcined powder of the mixture of alumina and β ″ -alumina is about 90%, which is a low value. According to this method, it was shown that the calcination powder has a β ″ conversion rate of almost 100% by crushing and molding and then sintering, but even in the calcination powder state, the β ″ conversion ratio is high. It is clear that it is better. For the reaction of alumina and lithium is higher than the reactivity of the alumina and sodium, Al 2 O 3 -Li 2 O-based composite oxide in a state of calcined powder is Al 2 O
It appears that it forms before the 3- Na 2 O-based composite oxides (β ″ -alumina and β-alumina) and slows the diffusion of sodium in alumina. May adversely affect lithium distribution.
【００１５】本発明は上記従来のβ″−アルミナの製造
に際する種々の問題の存在に鑑み、簡単で、かつ工業的
に原料の取扱い、毒性あるいは特性に問題がなく、アル
ミニウム原料や焼結条件の差による焼結体の特性の変化
を極力抑制しうるベータアルミナ電解質の製造方法を提
供しようとするものである。In view of the various problems involved in the production of the above-mentioned conventional β ″ -alumina, the present invention is simple and has no industrial problems in handling, toxicity or characteristics of the raw material, and aluminum raw material or sintering. An object of the present invention is to provide a method for producing a beta-alumina electrolyte capable of suppressing changes in the characteristics of a sintered body due to differences in conditions as much as possible.
【００１６】[0016]
【課題を解決するための手段】本発明はアルミニウム出
発原料とナトリウム出発原料を混合・仮焼してベータア
ルミナの仮焼粉を調製後、該仮焼粉と溶媒に可溶性のリ
チウムの出発原料とを混合してスラリを調製し、該スラ
リを乾燥・粉砕・成型後、焼結することを特徴とするベ
ータアルミナの電解質の製造方法である。According to the present invention, an aluminum starting material and a sodium starting material are mixed and calcined to prepare a calcined powder of beta-alumina, and the calcined powder is mixed with a solvent-soluble lithium starting material. Is mixed to prepare a slurry, and the slurry is dried, crushed, molded, and then sintered, and the method is a method for producing an electrolyte of beta-alumina.
【００１７】すなわち、アルミニウムとナトリウムの出
発原料を仮焼してβ″化率の高い仮焼粉を調製した後に
粉砕することにより、アルミナ出発原料の物性（一次粒
子径、比表面積等）に起因する仮焼粉物性の差を抑制す
る。その粉砕された仮焼粉を溶媒に可溶性のリチウム原
料の溶液に分散させスラリを調製し、液状でリチウムを
供給してリチウムの仮焼粉内の分散性を向上させる。さ
らにそのスラリを乾燥・粉砕・成型後に焼結することに
より拡散性の高いリチウムを反応させることでアルミナ
出発原料の物性に依存しない、特性の安定したベータア
ルミナ電解質を得るようにしたものである。That is, the aluminum and sodium starting materials are calcined to prepare a calcined powder having a high β ″ ratio, and then the powder is pulverized to cause physical properties (primary particle diameter, specific surface area, etc.) of the alumina starting material. The pulverized calcined powder is dispersed in a solvent-soluble lithium raw material solution to prepare a slurry, and lithium is supplied in a liquid state to disperse lithium in the calcined powder. In addition, the slurry is dried, pulverized, and molded and then sintered to react with highly diffusible lithium to obtain a beta-alumina electrolyte with stable properties that does not depend on the physical properties of the alumina starting material. It was done.
【００１８】[0018]
【作用】本発明のベータアルミナの製造法では仮焼粉の
状態でβ″化率の高い仮焼粉を調製することができる。
また、β″−アルミナの結晶安定化剤であるリチウム原
料に、溶媒に可溶性なリチウム出発原料を用いることに
よって微量成分であるリチウムの分散性を向上させるこ
とができる。また、アルミニウムとナトリウムの仮焼粉
にリチウムを高分散させ、焼結させることでβ″化率を
低下させるリチウムの影響を低減させることができる。
上記特徴によりリチウムの偏在のない高いβ″化率を示
す仮焼粉を用いることでβ″−アルミナ粒子の異常粒成
長を抑制することが可能となり、焼結体の強度あるいは
耐久性等の特性を向上させることができる。According to the method for producing beta-alumina of the present invention, it is possible to prepare a calcined powder having a high β ″ ratio in a calcined powder state.
Further, by using a solvent-soluble lithium starting material as the lithium raw material which is a β ″ -alumina crystal stabilizer, the dispersibility of lithium, which is a minor component, can be improved. By highly dispersing lithium in the fired powder and sintering it, it is possible to reduce the influence of lithium that lowers the β ″ conversion rate.
Due to the above characteristics, it is possible to suppress abnormal grain growth of β ″ -alumina particles by using a calcined powder showing a high β ″ conversion rate with no uneven distribution of lithium, and the characteristics such as strength or durability of the sintered body can be suppressed. Can be improved.
【００１９】また、本発明のベータアルミナの製造法で
はアルミニウム及びナトリウムの粉体原料から仮焼粉を
調製後、溶媒に可溶性なリチウム原料とのスラリを乾燥
・成型して焼結を行うものであるが、この方法では最も
一般的な従来法であるゼータ法の混合工程３回及び仮焼
工程２回に対し混合工程２回及び仮焼工程１回と大幅に
工程を減らすことができる。さらに、仮焼工程を施し、
粉砕することにより、原料アルミナの物性により変化す
る焼結体の特性を安定化させることができ、アルミニウ
ム原料の選択の自由度の増加及び焼結体の特性の安定化
を図ることができる。In the method for producing beta-alumina of the present invention, a calcined powder is prepared from aluminum and sodium powder raw materials, and a slurry with a solvent-soluble lithium raw material is dried and molded and sintered. However, in this method, the number of steps can be greatly reduced to two mixing steps and one calcination step as compared with three mixing steps and two calcination steps of the zeta method which is the most general conventional method. Furthermore, a calcination process is applied,
By pulverizing, it is possible to stabilize the characteristics of the sintered body that change depending on the physical properties of the raw material alumina, increase the degree of freedom in selecting the aluminum raw material and stabilize the characteristics of the sintered body.
【００２０】[0020]
【実施例】次に本発明を具体的な実施例により、さらに
詳細に説明する。工業的に電池としてベータアルミナ電
解質を用いる場合には通常片端を封じたチューブ状の焼
結体を使用する。上記チューブ状の焼結体を工業的に量
産するには造粒粉を用いて成型体を作成し、それを焼結
することによって得られる。そこで、この実施例では混
合原料スラリを仮焼した後、湿式粉砕したスラリを用い
てスプレードライ法により造粒粉を作成し、それを焼結
することによりベータアルミナ電解質を得る方法につい
てのべる。EXAMPLES Next, the present invention will be described in more detail with reference to specific examples. When a beta-alumina electrolyte is industrially used as a battery, a tube-shaped sintered body having one end sealed is usually used. In order to industrially mass-produce the above-mentioned tube-shaped sintered body, it is obtained by forming a molded body using granulated powder and sintering it. Therefore, in this embodiment, a method of obtaining a beta-alumina electrolyte by calcining a mixed raw material slurry, then producing a granulated powder by a spray dry method using a wet-milled slurry, and sintering the granulated powder will be described.
【００２１】先ず、一次粒子径が０．１、０．２５、
０．５、１．２及び２．０μｍという酸化アルミニウム
と炭酸ナトリウム選定した後、酸化アルミニウム及び炭
酸ナトリウムの別別のストックスラリを調製した。具体
的には１リットルのポットにジルコニアボールを入れ、
所定量の原料粉末とｎ−ブタノール及び分散剤（ポリエ
チレンイミン系）を投入して原料に応じた時間で混合を
行った。その調製条件を表１に示す。First, the primary particle size is 0.1, 0.25,
After selecting aluminum oxide and sodium carbonate of 0.5, 1.2 and 2.0 μm, another stock slurry of aluminum oxide and sodium carbonate was prepared. Specifically, put zirconia balls in a 1 liter pot,
A predetermined amount of raw material powder, n-butanol, and a dispersant (polyethyleneimine type) were added and mixed for a time corresponding to the raw material. The preparation conditions are shown in Table 1.
【００２２】[0022]
【表１】 [Table 1]
【００２３】次に得られた５種類の酸化アルミニウムス
ラリ及び炭酸ナトリウムスラリを２時間混合した。その
時の化学組成はβ″−アルミナの標準的組成である酸化
アルミニウム：９０．４重量％、酸化ナトリウム：８．
８５重量％及び酸化リチウム：０．７５重量％を基準
に、酸化アルミニウム＝９０．４ｗｔ％：酸化ナトリウ
ム＝８．８５ｗｔ％のモル比で酸化アルミニウム：酸化
ナトリウム＝６．２０９になるように調製した。また、
比較のために、Ｌｉ−ブトキシドのブタノール溶液を用
いて酸化物ベースで標準組成になるように３成分を含む
スラリも調製した。Next, the obtained five kinds of aluminum oxide slurries and sodium carbonate slurries were mixed for 2 hours. The chemical composition at that time was a standard composition of β ″ -alumina: aluminum oxide: 90.4% by weight, sodium oxide: 8.
Based on 85% by weight and lithium oxide: 0.75% by weight, aluminum oxide = sodium oxide = 6.209 at a molar ratio of aluminum oxide = 90.4% by weight sodium oxide = 8.85% by weight. . Also,
For comparison, a slurry containing three components was also prepared to a standard composition on an oxide basis using a solution of Li-butoxide in butanol.
【００２４】得られたスラリをロータリエバポレータで
濃縮後、１２０℃の乾燥器にて１昼夜乾燥させた。その
乾燥物を粉砕し５００μｍのフルイを通した後、仮焼に
供した。仮焼は５℃／ｍｉｎで昇温後、１２５０℃で２
時間保持し、５℃／ｍｉｎで降温するものとした。The obtained slurry was concentrated with a rotary evaporator and then dried with a drier at 120 ° C. for one day. The dried product was crushed, passed through a 500 μm sieve, and then calcined. For calcination, raise the temperature at 5 ° C / min and then at 1250 ° C for 2
The temperature was maintained for 5 hours and the temperature was lowered at 5 ° C / min.
【００２５】得られた仮焼粉のアルミナ原料の一次粒子
径とβ″−アルミナの生成率（β″化率）の関係を図１
に示す。ここでβ″化率は以下の式で定義した。 β″化率＝Ｉβ″（0210) ×100 ／Ｉβ″（0210) ＋Ｉ
β（017) 但し、Ｉβ″（0210) はβ″−アルミナの（0210) ピー
ク高さ、Ｉβ（017)はβ−アルミナの（017)ピーク高さ
である。The relationship between the primary particle diameter of the alumina raw material of the obtained calcined powder and the β ″ -alumina production rate (β ″ conversion rate) is shown in FIG.
Shown in. Here, the β ″ conversion rate is defined by the following formula: β ″ conversion rate = Iβ ″ (0210) × 100 / Iβ ″ (0210) + I
β (017) where Iβ ″ (0210) is the (0210) peak height of β ″ -alumina, and Iβ (017) is the (017) peak height of β-alumina.
【００２６】図１より、酸化アルミニウム及び酸化ナト
リウムの混合物のβ″化率は酸化アルミニウムの一次粒
子径に依存せず、高い値を示した。また、図１にはＬｉ
−ブトキシドを用いた３成分を含むスラリの仮焼粉の
β″化率を示すが、この系ではβ″化率の酸化アルミニ
ウムの一次粒子径への依存性がみられる。From FIG. 1, the β ″ conversion of the mixture of aluminum oxide and sodium oxide showed a high value without depending on the primary particle diameter of aluminum oxide.
-The β "conversion ratio of the calcined powder of the slurry containing three components using butoxide is shown. In this system, the β" conversion ratio depends on the primary particle diameter of aluminum oxide.
【００２７】得られた仮焼粉は粒成長しているため、１
リットルのポットにて平均粒径が１μｍ以下になるまで
ｎ−ブタノール中で湿式粉砕を行った。湿式粉砕後のス
ラリにＬｉ−ブトキシドのブタノール溶液を酸化物ベー
スでβ″−アルミナの標準組成になるように添加した。
さらにスプレードライに供するためにｎ−ブタノールを
用いて希釈し１００ｃｐ程度に粘度調整を行い、その混
合スラリを２時間混合して合計５種類のスラリを調製し
た。その後、スプレードライにて５種類の造粒粉を調製
した。その操作条件は室温とし、ディスクの回転数を１
４０００ｒｐｍとした。得られた造粒粉の粒径は平均粒
径で８０〜１００μｍの球状のものであった。なお、こ
の実施例では溶媒にｎ−ブタノール、可溶性のリチウム
出発原料にＬｉ−ブトキシドを用いているが、他の有機
溶媒とそれに可溶な有機リチウムあるいは水と水に可溶
なリチウム塩（例えば硝酸リチウム）等の種々の組合せ
が可能である。Since the obtained calcined powder has grown grains, 1
Wet grinding was carried out in n-butanol in a liter pot until the average particle size was 1 μm or less. A butanol solution of Li-butoxide was added to the slurry after the wet pulverization so as to have a standard composition of β ″ -alumina on an oxide basis.
Further, for use in spray drying, the mixture was diluted with n-butanol to adjust the viscosity to about 100 cp, and the mixed slurry was mixed for 2 hours to prepare a total of 5 types of slurries. Then, 5 types of granulated powder were prepared by spray drying. The operating conditions are room temperature and the disk rotation speed is 1
It was set to 4000 rpm. The particle size of the obtained granulated powder was spherical with an average particle size of 80 to 100 μm. In this example, n-butanol is used as the solvent and Li-butoxide is used as the soluble lithium starting material, but other organic solvents and soluble organic lithium or water and water soluble lithium salts (for example, Various combinations such as lithium nitrate) are possible.
【００２８】その造粒粉を用いて、径２０ｍｍの円形金
型を用いて一軸圧１００ｋｇ／ｃｍ 2 で成型し、さらに
それをラバーに入れてＣＩＰ（冷間静水圧加圧）で１．
５ｔ／ｃｍ2 の圧力にて５分間保持して成型体とした。
得られた成型体を５℃／ｍｉｎの昇温速度で昇温し、１
６００℃で１０分保持後、１４５０℃で５時間のアニー
ル処理を施し焼結体を作製した。Using the granulated powder, circular gold with a diameter of 20 mm
Uniaxial pressure 100kg / cm using the mold 2Molded with
Put it in rubber and CIP (cold isostatic pressurization) 1.
5t / cm2The pressure was maintained for 5 minutes to obtain a molded body.
The obtained molded body is heated at a temperature rising rate of 5 ° C./min to
After holding at 600 ℃ for 10 minutes, anneal at 1450 ℃ for 5 hours
And a sintered body was produced.
【００２９】５種類の焼結体の密度は３．１８ｇ／ｃｍ
3 以上で、相対密度は９７％以上（理論密度＝３．２８
ｇ／ｃｍ3 ）であった。その時の各焼結体のアルミナ原
料の一次粒子径とβ″化率の関係を図２に示す。また、
比較のために仮焼粉を調製せず３成分を含有するスラリ
（一次粒子径の異なる５種類のアルミナ原料を使用）を
成型して、１２５０℃で２時間保持後に続いて１６００
℃で１０分、１４５０℃で５時間の熱処理を行い調製し
た焼結体のβ″化率をも図２に併せて示す。なお、従来
法であるゼータ法により調製した焼結体のβ″化率は１
００％である。The density of the five kinds of sintered bodies is 3.18 g / cm.
At 3 or more, the relative density is 97% or more (theoretical density = 3.28
g / cm 3 ). The relationship between the primary particle diameter of the alumina raw material and the β ″ conversion rate of each sintered body at that time is shown in FIG.
For comparison, a calcinated powder was not prepared, and a slurry containing 3 components (using 5 kinds of alumina raw materials having different primary particle diameters) was molded and held at 1250 ° C. for 2 hours, followed by 1600.
The β ″ ratio of the sintered body prepared by heat treatment at 10 ° C. for 10 minutes and 1450 ° C. for 5 hours is also shown in FIG. 2. The β ″ of the sintered body prepared by the conventional zeta method is also shown. The conversion rate is 1
It is 00%.
【００３０】図２より、仮焼粉調製を行なうことによ
り、一次粒子径が２．０μｍの系以外ではほぼβ″−ア
ルミナ単相の焼結体を作製できた。すなわち、本発明方
法によればβ″化率のアルミナ原料依存性を低減するこ
とができることが明らかである。From FIG. 2, it was possible to prepare a sintered body of almost β ″ -alumina single phase except for the system having a primary particle diameter of 2.0 μm by preparing the calcined powder. That is, according to the method of the present invention. For example, it is clear that the dependence of the β ″ conversion on the alumina raw material can be reduced.
【００３１】（実施例２）β″−アルミナ中の酸化リチ
ウム量を変化させた焼結体を実施例１と同様の製法で調
製した。具体的には、β″−アルミナの標準的組成であ
る酸化アルミニウム（Ａｌ2 Ｏ3 ）：９０．４重量％、
酸化ナトリウム（Ｎａ2 Ｏ）：８．８５重量％及び酸化
リチウム（Ｌｉ2 Ｏ）：０．７５重量％を基準に、Ａｌ
2 Ｏ3 ＝９０．４ｗｔ％：Ｎａ2 Ｏ＝８．８５ｗｔ％の
モル比でＡｌ2 Ｏ3 ：Ｎａ2 Ｏ＝６．２０９になるよう
に調製したスラリに、Ｌｉ−ブトキシド溶液を添加し、
Ｌｉ2 Ｏ／（Ａｌ2 Ｏ3 ＋Ｎａ2 Ｏ＋Ｌｉ2 Ｏ）比が
０．２５、０．５、０．７５、１．００重量％になるよ
うに調製した。また、比較のために３成分を同時に混合
して、仮焼粉を調製せずに焼結体を作製した。(Example 2) A sintered body in which the amount of lithium oxide in β "-alumina was changed was prepared in the same manner as in Example 1. Specifically, a standard composition of β" -alumina was used. Aluminum oxide (Al 2 O 3 ): 90.4% by weight,
Based on sodium oxide (Na 2 O): 8.85% by weight and lithium oxide (Li 2 O): 0.75% by weight, Al
A Li-butoxide solution was added to a slurry prepared so that Al 2 O 3 : Na 2 O = 6.209 at a molar ratio of 2 O 3 = 90.4 wt%: Na 2 O = 8.85 wt%,
It was prepared so that the Li 2 O / (Al 2 O 3 + Na 2 O + Li 2 O) ratio would be 0.25, 0.5, 0.75, and 1.00% by weight. For comparison, three components were mixed at the same time to prepare a sintered body without preparing a calcined powder.
【００３２】得られた焼結体の３００℃における導電率
の値を図３に示す。図３において、Ｌｉ2 Ｏ量の増加に
伴い導電率は向上することがわかる。また、本発明の製
法では３成分を同時に混合して焼結体を作製する製法に
比較して、Ｌｉ2 Ｏ量による導電率の変化が小さく、化
学組成の変動に伴う特性の変化を低減することができる
ことが明らかである。The electric conductivity value of the obtained sintered body at 300 ° C. is shown in FIG. In FIG. 3, it can be seen that the conductivity improves as the amount of Li 2 O increases. Further, in the production method of the present invention, the change in conductivity due to the amount of Li 2 O is smaller than that in the production method in which three components are simultaneously mixed to produce a sintered body, and the change in characteristics due to the change in chemical composition is reduced. It is clear that you can.
【００３３】なお、標準組成（Ｌｉ2 Ｏ＝０．７５ｗｔ
％）における本発明の製法、３成分を同時に混合して焼
結体を作製する製法及び従来法（ゼータ法）の３種類の
焼結体の導電率は約０．２０Ｓｃｍ-1とほぼ同じ値を示
した。The standard composition (Li 2 O = 0.75 wt.
%), The electrical conductivity of the three types of sintered bodies, that is, the manufacturing method of the present invention in which the three components are simultaneously mixed to produce a sintered body and the conventional method (zeta method) is approximately 0.20 Scm −1. showed that.
【００３４】上記３種類（本発明、３成分同時混合、ゼ
ータ法）の焼結体研磨面を熱燐酸（１６０℃）で１分間
エッチングした組織の光学顕微鏡写真をそれぞれ図４、
図５及び図６に示す。これらの図より、その組織は図４
（本発明）が最も微細で、図６（ゼータ法）が最も粗大
で、図５（３成分同時混合）はその中間の大きさであ
る。Optical microscope photographs of the structures obtained by etching the polished surfaces of the above three types (the present invention, three-component simultaneous mixing, zeta method) for 1 minute with hot phosphoric acid (160 ° C.), respectively, are shown in FIG.
This is shown in FIGS. 5 and 6. From these figures, the organization is shown in Figure 4.
(Invention) is the finest, FIG. 6 (Zeta method) is the coarsest, and FIG. 5 (simultaneous mixing of three components) has an intermediate size.
【００３５】ベータアルミナは組織が粗大（粒成長）な
程、その導電率は増加するが、その強度は低下するとい
う一般的な傾向をもつ。そのため、ほぼ同じ導電率を示
す本実施例において述べた３種類の焼結体の中で、最も
微細な組織を示す本発明の焼結体が強度が高く、電池と
しての耐久性が優れていることを示している。Beta-alumina has a general tendency that its conductivity increases as its structure becomes coarser (grain growth), but its strength decreases. Therefore, the sintered body of the present invention having the finest structure among the three types of sintered bodies having substantially the same electric conductivity described in this example has high strength and excellent durability as a battery. It is shown that.
【００３６】[0036]
【発明の効果】以上説明したように、本発明によれば、
従来法により調製したものと比較して、導電性を低下さ
せずに微細な組織をもつベータアルミナを従来法よりも
簡便な方法により調製することができ、電池用電解質と
しての耐久性が向上する。また、アルミナ原料の種類に
よらず再現性のある特性をもち、かつ酸化リチウム量に
よる特性の変化の少ないβ″−アルミナを調製できるた
め、工業的な製法による電池用電解質としての信頼性が
向上する。As described above, according to the present invention,
Compared with the one prepared by the conventional method, beta-alumina having a fine structure can be prepared by a simpler method than the conventional method without lowering the conductivity, and the durability as a battery electrolyte is improved. . Further, β ″ -alumina, which has reproducible characteristics regardless of the type of alumina raw material and has little change in characteristics depending on the amount of lithium oxide, can improve reliability as an electrolyte for batteries by an industrial manufacturing method. To do.
【図１】本発明の実施例１における仮焼粉に対するアル
ミナ原料の一次粒子径とβ″化率の関係を示す図表。FIG. 1 is a chart showing a relationship between a primary particle diameter of an alumina raw material and a β ″ conversion rate with respect to a calcined powder in Example 1 of the present invention.
【図２】本発明の実施例１における焼結体に対するアル
ミナ原料の一次粒子径とβ″化率の関係を示す図表。FIG. 2 is a chart showing a relationship between a primary particle diameter of an alumina raw material and a β ″ conversion rate with respect to a sintered body in Example 1 of the present invention.
【図３】本発明の実施例２における焼結体の酸化リチウ
ム含有量と導電率の関係を示す図表。FIG. 3 is a chart showing the relationship between the lithium oxide content and the electrical conductivity of a sintered body in Example 2 of the present invention.
【図４】本発明の実施例２における焼結体のミクロ組織
を示す光学顕微鏡写真。FIG. 4 is an optical micrograph showing a microstructure of a sintered body in Example 2 of the present invention.
【図５】本発明の実施例２における３成分を同時に混合
する製法にて作製した比較例としての焼結体のミクロ組
織を示す光学顕微鏡写真。FIG. 5 is an optical micrograph showing a microstructure of a sintered body as a comparative example produced by a method of simultaneously mixing the three components in Example 2 of the present invention.
【図６】本発明の実施例２における従来法（ゼータ法）
により作製した焼結体のミクロ組織を示す光学顕微鏡写
真。FIG. 6 is a conventional method (zeta method) in Embodiment 2 of the present invention.
An optical micrograph showing the microstructure of the sintered body produced by.
─────────────────────────────────────────────────────
─────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成５年１１月１６日[Submission date] November 16, 1993
【手続補正１】[Procedure Amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】図面の簡単な説明[Name of item to be corrected] Brief description of the drawing
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【図面の簡単な説明】[Brief description of drawings]
【図１】本発明の実施例１における仮焼粉に対するアル
ミナ原料の一次粒子径とβ″化率の関係を示す図表。FIG. 1 is a chart showing a relationship between a primary particle diameter of an alumina raw material and a β ″ conversion rate with respect to a calcined powder in Example 1 of the present invention.
【図２】本発明の実施例１における焼結体に対するアル
ミナ原料の一次粒子径とβ″化率の関係を示す図表。FIG. 2 is a chart showing a relationship between a primary particle diameter of an alumina raw material and a β ″ conversion rate with respect to a sintered body in Example 1 of the present invention.
【図３】本発明の実施例２における焼結体の酸化リチウ
ム含有量と導電率の関係を示す図表。FIG. 3 is a chart showing the relationship between the lithium oxide content and the electrical conductivity of a sintered body in Example 2 of the present invention.
【図４】本発明の実施例２における焼結体の結晶構造を
示す光学顕微鏡写真。FIG. 4 is an optical micrograph showing a crystal structure of a sintered body in Example 2 of the present invention.
【図５】本発明の実施例２における３成分を同時に混合
する製法にて作製した比較例としての焼結体の結晶構造
を示す光学顕微鏡写真。FIG. 5 is an optical micrograph showing a crystal structure of a sintered body as a comparative example produced by a method of simultaneously mixing the three components in Example 2 of the present invention.
【図６】本発明の実施例２における従来法（ゼータ法）
により作製した焼結体の結晶構造を示す顕微鏡写真。FIG. 6 is a conventional method (Zeta method) in Embodiment 2 of the present invention.
A micrograph showing the crystal structure of the sintered body produced by.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 水流 靖彦 神奈川県横浜市金沢区幸浦一丁目８番地１ 三菱重工業株式会社基盤技術研究所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuhiko Mizutani 1-8-1 Koura, Kanazawa-ku, Yokohama, Kanagawa Prefecture Mitsubishi Heavy Industries, Ltd.
Claims (1)
原料を混合・仮焼してベータアルミナの仮焼粉を調製
後、該仮焼粉と溶媒に可溶性のリチウムの出発原料とを
混合してスラリを調製し、該スラリを乾燥・粉砕・成型
後、焼結することを特徴とするベータアルミナの電解質
の製造方法。1. A slurry is prepared by mixing and calcining an aluminum starting material and a sodium starting material to prepare a calcined powder of beta-alumina, and then mixing the calcined powder and a starting material of lithium soluble in a solvent. Then, the slurry is dried, pulverized, molded, and then sintered, and a method for producing an electrolyte of beta-alumina.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4227814A JP2961021B2 (en) | 1992-08-05 | 1992-08-05 | Method for producing beta alumina electrolyte |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4227814A JP2961021B2 (en) | 1992-08-05 | 1992-08-05 | Method for producing beta alumina electrolyte |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06116016A true JPH06116016A (en) | 1994-04-26 |
| JP2961021B2 JP2961021B2 (en) | 1999-10-12 |
Family
ID=16866800
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4227814A Expired - Lifetime JP2961021B2 (en) | 1992-08-05 | 1992-08-05 | Method for producing beta alumina electrolyte |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2961021B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013065397A (en) * | 2011-09-15 | 2013-04-11 | Honda Motor Co Ltd | Electrode active material, and method of manufacturing the same |
-
1992
- 1992-08-05 JP JP4227814A patent/JP2961021B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013065397A (en) * | 2011-09-15 | 2013-04-11 | Honda Motor Co Ltd | Electrode active material, and method of manufacturing the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2961021B2 (en) | 1999-10-12 |
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