JPH0345554A - Production of beta"-alumina sintered compact - Google Patents
Production of beta"-alumina sintered compactInfo
- Publication number
- JPH0345554A JPH0345554A JP1180593A JP18059389A JPH0345554A JP H0345554 A JPH0345554 A JP H0345554A JP 1180593 A JP1180593 A JP 1180593A JP 18059389 A JP18059389 A JP 18059389A JP H0345554 A JPH0345554 A JP H0345554A
- Authority
- JP
- Japan
- Prior art keywords
- alumina
- beta
- raw material
- water
- sintered body
- 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
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 title claims abstract description 12
- 238000004519 manufacturing process Methods 0.000 title claims description 23
- 239000013078 crystal Substances 0.000 claims abstract description 57
- RPMPQTVHEJVLCR-UHFFFAOYSA-N pentaaluminum;sodium;oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[Na+].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3] RPMPQTVHEJVLCR-UHFFFAOYSA-N 0.000 claims abstract description 28
- 239000002994 raw material Substances 0.000 claims abstract description 20
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 10
- 238000002156 mixing Methods 0.000 claims abstract description 9
- 238000010298 pulverizing process Methods 0.000 claims abstract description 9
- 238000010304 firing Methods 0.000 claims description 11
- 239000002245 particle Substances 0.000 claims description 8
- 239000000203 mixture Substances 0.000 abstract description 13
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 abstract description 9
- 238000001694 spray drying Methods 0.000 abstract description 9
- BNOODXBBXFZASF-UHFFFAOYSA-N [Na].[S] Chemical compound [Na].[S] BNOODXBBXFZASF-UHFFFAOYSA-N 0.000 abstract description 6
- 238000001354 calcination Methods 0.000 abstract description 5
- 239000003513 alkali Substances 0.000 abstract description 3
- 239000000843 powder Substances 0.000 abstract description 3
- 230000015572 biosynthetic process Effects 0.000 abstract description 2
- 239000003792 electrolyte Substances 0.000 abstract description 2
- 239000008187 granular material Substances 0.000 abstract 1
- 239000011369 resultant mixture Substances 0.000 abstract 1
- 229910052594 sapphire Inorganic materials 0.000 abstract 1
- 239000000126 substance Substances 0.000 abstract 1
- 238000000034 method Methods 0.000 description 30
- 238000006243 chemical reaction Methods 0.000 description 14
- 229910001415 sodium ion Inorganic materials 0.000 description 8
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 6
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 6
- 229910052782 aluminium Inorganic materials 0.000 description 6
- 239000007864 aqueous solution Substances 0.000 description 6
- 239000011734 sodium Substances 0.000 description 6
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 description 5
- 230000002159 abnormal effect Effects 0.000 description 5
- 230000006866 deterioration Effects 0.000 description 5
- 239000003381 stabilizer Substances 0.000 description 5
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- 238000013001 point bending Methods 0.000 description 4
- 239000011362 coarse particle Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- 238000000465 moulding Methods 0.000 description 3
- 239000003960 organic solvent Substances 0.000 description 3
- 238000005245 sintering Methods 0.000 description 3
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 2
- 229910013522 LizC Inorganic materials 0.000 description 2
- KKCBUQHMOMHUOY-UHFFFAOYSA-N Na2O Inorganic materials [O-2].[Na+].[Na+] KKCBUQHMOMHUOY-UHFFFAOYSA-N 0.000 description 2
- FKNQFGJONOIPTF-UHFFFAOYSA-N Sodium cation Chemical compound [Na+] FKNQFGJONOIPTF-UHFFFAOYSA-N 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 description 2
- 229910052808 lithium carbonate Inorganic materials 0.000 description 2
- 239000011777 magnesium Substances 0.000 description 2
- YIXJRHPUWRPCBB-UHFFFAOYSA-N magnesium nitrate Chemical compound [Mg+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O YIXJRHPUWRPCBB-UHFFFAOYSA-N 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000011812 mixed powder Substances 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- 229910052708 sodium Inorganic materials 0.000 description 2
- 229910000029 sodium carbonate Inorganic materials 0.000 description 2
- 239000007784 solid electrolyte Substances 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 229910000873 Beta-alumina solid electrolyte Inorganic materials 0.000 description 1
- 101100348017 Drosophila melanogaster Nazo gene Proteins 0.000 description 1
- FUJCRWPEOMXPAD-UHFFFAOYSA-N Li2O Inorganic materials [Li+].[Li+].[O-2] FUJCRWPEOMXPAD-UHFFFAOYSA-N 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 239000004411 aluminium Substances 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 239000003125 aqueous solvent Substances 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 244000309464 bull Species 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- XUCJHNOBJLKZNU-UHFFFAOYSA-M dilithium;hydroxide Chemical compound [Li+].[Li+].[OH-] XUCJHNOBJLKZNU-UHFFFAOYSA-M 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- YQNQTEBHHUSESQ-UHFFFAOYSA-N lithium aluminate Chemical compound [Li+].[O-][Al]=O YQNQTEBHHUSESQ-UHFFFAOYSA-N 0.000 description 1
- 229910001947 lithium oxide Inorganic materials 0.000 description 1
- ZLNQQNXFFQJAID-UHFFFAOYSA-L magnesium carbonate Chemical compound [Mg+2].[O-]C([O-])=O ZLNQQNXFFQJAID-UHFFFAOYSA-L 0.000 description 1
- 239000001095 magnesium carbonate Substances 0.000 description 1
- 229910000021 magnesium carbonate Inorganic materials 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 239000007773 negative electrode material Substances 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 239000007774 positive electrode material Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000000779 smoke Substances 0.000 description 1
- 229910001948 sodium oxide Inorganic materials 0.000 description 1
- HYHCSLBZRBJJCH-UHFFFAOYSA-N sodium polysulfide Chemical compound [Na+].S HYHCSLBZRBJJCH-UHFFFAOYSA-N 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
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
- Y02E60/10—Energy storage using batteries
Landscapes
- Compositions Of Oxide Ceramics (AREA)
- Secondary Cells (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明はβ″アルミナ焼結体の製造方法に関するもので
ある。更に詳しくはナトリウム−硫黄電池等に好適なナ
トリウムイオン電導に対して低いイオン伝導抵抗率を有
し、緻密で高強度のβ″アルごす焼結体を安価に製造し
得る製造方法に関するものである。Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for producing a β'' alumina sintered body. The present invention relates to a method of manufacturing a dense, high-strength β'' aluminum sintered body having conductive resistivity at a low cost.
（従来の技術及びその問題点）
ナトリウム−硫黄電池は、３００〜３５０°Ｃで作動す
る高温型の二次電池である。溶融ナトリウムを負極活物
質、溶融硫黄または多硫化ナトリウムを正極活物質とし
て使用し、電解質として、ナトリウムイオン伝導性を有
するβ−アルミナ（Ｎａ、０・１１ ＡｆｚＯｚ）、β
″−アルξす（ＮａｚＯＨ５Ａ １ ｚｏ３）等の固体
電解質からなる焼結体が用いられる。ナトリウム−硫黄
電池では、特に良好な性能と長い使用寿命が要求される
ため、ナトリウム−硫黄電池用固体電解質焼結体には以
下の特性が必要である。(Prior Art and its Problems) A sodium-sulfur battery is a high-temperature secondary battery that operates at 300 to 350°C. Molten sodium is used as the negative electrode active material, molten sulfur or sodium polysulfide is used as the positive electrode active material, and β-alumina (Na, 0.11 AfzOz), which has sodium ion conductivity, is used as the electrolyte.
A sintered body made of a solid electrolyte such as NazOH5A 1 zo3 is used. Since sodium-sulfur batteries require particularly good performance and a long service life, solid electrolytes for sodium-sulfur batteries are used. The sintered body must have the following properties.
（１）高密度で通気性がないこと
（２）機械的強度が高いこと
（３）イオン伝導度が良好なこと
（４）ベータアルくす結晶の粒径が均一で１００μｍ以
上の粗大粒子がないこと
このような特性を有するβ″アルミナ焼結体を製造する
ため種々の製造法が提案されている。(1) High density and no air permeability (2) High mechanical strength (3) Good ionic conductivity (4) Beta-Alx crystal grain size is uniform and there are no coarse particles of 100 μm or more Various manufacturing methods have been proposed for manufacturing β″ alumina sintered bodies having such characteristics.
例えば、ＬｉｔＯ安定化β″アルミナ焼結体の製造法と
しては、予めＮａｚＣＯ３とα−Ａ ｆ ２０３の混合
物を仮焼してβおよびβ″アルミナが混しった仮焼物を
形成しておき、また別途ＬｉｚＯ・５Ａｆｚ０３（ゼー
タリチウムアルミネート）を混合・仮焼して作威し、こ
れら二種類の仮焼物をさらにもう一度有機溶媒中で粉砕
・混合し噴霧して原料とするゼータプロセスが特公昭５
７−１５０６３号で知られている。For example, as a method for producing a LitO-stabilized β″ alumina sintered body, a mixture of NazCO3 and α-A f 203 is calcined in advance to form a calcined product in which β and β″ alumina are mixed; The Zeta process was developed in 1973, in which LizO・5Afz03 (zeta lithium aluminate) was mixed and calcined, and these two types of calcined products were crushed and mixed in an organic solvent again, and then sprayed to obtain a raw material.
It is known as No. 7-15063.
ゼータプロセスでは、安定化剤であるＬｉ２Ｏの分散性
が向上するため、粗大粒子の形成が抑制される。In the zeta process, the dispersibility of Li2O, which is a stabilizer, is improved, so formation of coarse particles is suppressed.
しかし、原料調製時に２種類の仮焼物を作成するため、
仮焼の工程が２回必要なこと、および二種類の仮焼物の
粉砕・混合時にβおよびβ″アルミナ仮焼物の水による
分解を抑制するために、有機溶媒を使用する必要がある
ため、工程が複雑で、コスト高になる欠点がある。また
焼成スケジュールも、例えば２００″Ｃ／ｍｉｎ以上急
昇温し、１６００°Ｃ前後の温度で５〜１０分間保持後
１５００°Ｃ以下の温度で数時間焼鈍するという複雑な
もので極めて高度な焼成技術を要する。However, since two types of calcined products are created when preparing raw materials,
Because the calcination process is required twice, and because it is necessary to use an organic solvent to suppress the decomposition of the β and β″ alumina calcined products by water when pulverizing and mixing the two types of calcined products, the process is difficult. It has the disadvantage of being complicated and expensive. Also, the firing schedule is such that, for example, the temperature is rapidly raised at 200"C/min or more, held at a temperature of around 1600°C for 5 to 10 minutes, and then heated at a temperature of 1500°C or less for several seconds. It is a complex process that involves time annealing and requires extremely advanced firing technology.
一方、ゼータプロセスに対して現在注目されているのが
水溶液噴霧乾燥法である。水溶液噴霧乾燥法は、水溶性
のアルカリ原料種を直接水溶媒中に溶解混合し、スラリ
ー調整したものを噴霧乾燥して成形用顆粒原料を得る製
法で、５ＳＳＤプロセス（Ｓｌｕｒｒｙ ５ｏｌｕｔｉ
ｏｎ ５ｐｒａｙ Ｄｒｙｉｎｇ）と呼ばれ、将来のβ
″アルξ袋管量産のため、原料処理工程の簡略化と低コ
スト化に有効と考えられる。しかし、５ＳＳＤプロセス
によるβ″アル旦す焼結体は、従来はβ″化率がまだ不
十分で、イオン伝導抵抗率が高く、これらの特性改良が
課題となっていた。On the other hand, an aqueous solution spray drying method is currently attracting attention as opposed to the Zeta process. The aqueous solution spray drying method is a manufacturing method in which water-soluble alkaline raw materials are directly dissolved and mixed in an aqueous solvent, and the prepared slurry is spray-dried to obtain a granular raw material for molding.
on 5play Drying), and future β
Due to the mass production of "Al ξ bag tubes, it is considered effective in simplifying the raw material processing process and reducing costs. However, the β" aluminum sintered body produced by the 5SSD process is still insufficient in the β" conversion rate. However, it has a high ionic conduction resistivity, and improving these characteristics has been an issue.
（発明が解決しようとする課題）
本発明の課題は、β″化率が高く、イオン伝導抵抗率を
低くでき、強度も充分なβ″アルミナ焼結体及びその製
造方法を提供することである。(Problems to be Solved by the Invention) An object of the present invention is to provide a β″ alumina sintered body having a high β″ rate, low ionic conduction resistivity, and sufficient strength, and a method for manufacturing the same. .
（課題を解決するための手段）
本発明は、水溶性アルカリ原料種とアルミナ原料とを水
を用いて混合粉砕した後、噴霧乾燥して造粒し、次いで
成形、焼成を行うβ″アルミナ焼結体の製造方法におい
て、前記混合粉砕後に結晶相の主成分がβ″アルミナ相
からなりかつ平均粒径が１μｍ以上、９μｍ以下のβ″
アルミナ種結晶を２重量％以上、４５重量％以下添加混
合することを特徴とするβ″アル旦焼結体の製造方法に
係るものである。(Means for Solving the Problems) The present invention provides a β'' alumina sintering process in which a water-soluble alkali raw material and an alumina raw material are mixed and pulverized using water, then granulated by spray drying, and then shaped and fired. In the method for producing aggregates, after the mixing and pulverization, the main component of the crystal phase is β'' alumina phase and the average particle size is 1 μm or more and 9 μm or less.
The present invention relates to a method for producing a β'' aluminium sintered body characterized by adding and mixing alumina seed crystals in an amount of 2% by weight or more and 45% by weight or less.
（作 用）
本発明に係わるβ″アルミナ焼結体の製造方法では、水
溶性のアルカリ原料種とアル【す原料を水を用いて混合
粉砕した後に、β″アルミナ粉砕物を種結晶として添加
することが、結晶体のβ″化率を向上させ、イオン伝導
抵抗率を低下させるために重要である。(Function) In the method for producing a β″ alumina sintered body according to the present invention, a water-soluble alkaline raw material and an alkaline raw material are mixed and pulverized using water, and then a β″ alumina pulverized product is added as a seed crystal. It is important to improve the β″ conversion rate of the crystal and reduce the ion conduction resistivity.
この際、種結晶の平均粒径を１〜９μｍにして、添加量
を２〜４５重量％にすると、焼結体中の結晶子が均一に
成長するため、強度が劣化することがない。平均粒径を
１μｍ未満にすると、マトリックスに吸収されて消失す
る種結晶が増えて種結晶が粒成長の核としての働きを発
現しないため、添加効果が不充分となり、部分的な異常
粒成長が起って強度が劣化する。平均粒径が９μｍを越
えると、種結晶の数が不足して異常粒成長が生し、強度
劣化が起こる。また種結晶の最大径は４４μｍ以下が好
ましく、仮に４４μｍを越える場合には、粗大な種結晶
を中心にして異常ね成長が起きたり、種結晶の焼結性が
不足して強度劣化が起こる。種結晶の添加量が２重量％
未満では、β″化率が不充分で、イオン伝導抵抗率が大
きく、また異常粒成長も起って強度も低下する。さらに
種結晶の添加量が４５重量％を越えると成形棒の焼結性
が低下して焼結体強度が低下する。At this time, if the average grain size of the seed crystals is 1 to 9 μm and the amount added is 2 to 45% by weight, the crystallites in the sintered body will grow uniformly, so that the strength will not deteriorate. If the average grain size is less than 1 μm, more seed crystals will be absorbed into the matrix and disappear, and the seed crystals will not function as grain growth nuclei, resulting in insufficient addition effects and partial abnormal grain growth. This causes the strength to deteriorate. When the average grain size exceeds 9 μm, the number of seed crystals becomes insufficient, causing abnormal grain growth and deterioration of strength. Further, the maximum diameter of the seed crystal is preferably 44 μm or less, and if it exceeds 44 μm, abnormal growth may occur around the coarse seed crystal, or the sinterability of the seed crystal may be insufficient, resulting in deterioration of strength. The amount of seed crystal added is 2% by weight.
If the amount is less than 45% by weight, the β'' rate will be insufficient, the ion conduction resistivity will be large, abnormal grain growth will occur, and the strength will decrease.Furthermore, if the amount of seed crystals added exceeds 45% by weight, the formed rod will not sinter. The strength of the sintered body decreases.
以上述べたように本発明では、製造コストが安価なβ″
アルミナ焼結体の水溶液噴霧乾燥法製造プロセスにおい
て、高イオン伝導性と高強度性を両立させるためにβ″
アルミナ焼結体粉砕物を適量添加し、β″化率の向上と
、微構造の均一性を実現したものである。As mentioned above, in the present invention, β″
In the aqueous solution spray drying manufacturing process of alumina sintered bodies, β''
By adding an appropriate amount of pulverized alumina sintered material, we have achieved an improvement in the β″ conversion rate and a uniform microstructure.
上記種結晶の平均粒径は２〜５μｍが更に好ましく、種
結晶の添加量は５〜３０重量％が更に好ましい。The average particle size of the seed crystals is more preferably 2 to 5 μm, and the amount of seed crystals added is still more preferably 5 to 30% by weight.
（実施例）
第１図はβ″アルミナ焼結体の水噴霧乾燥法製造プロセ
スにβ″アルミナ焼結体粉砕物を種結晶として添加する
本発明のフローチャートである。(Example) FIG. 1 is a flowchart of the present invention in which a pulverized β'' alumina sintered body is added as a seed crystal to a water spray drying process for producing a β″ alumina sintered body.
本例では、Ａ ｌ ｚｏｉ源としてｃｒ−Ａｊ２２０３
、Ｎａ、０源として水溶性のＮａＯＨ１安定化剤のＭｇ
Ｏ、ＬｉｚＯｆｉとしてはＭｇ（ＮＯ３） Ｚ・６１１
２０．門ｇｃＯ，およびＬｉ０）ｌを用いた、また比較
のために、ゼータプロセス用の原料として、Ａｊ２２Ｃ
ｈ源として（ｘ ＡｌｚＯｚ、ＮａｚＯ源としてＮａ
２ＧＯ，、、ＮａＯＨ安定化剤のＭｇＯ、ＬｉｚＣ源と
しては門ｇｃｏ、、 ＬｉｚＣ（ｈおよびＬｉＯＨを用
いた。In this example, cr-Aj2203 is used as the Al zoi source.
, Na, 0 as a water-soluble NaOH1 stabilizer Mg as a source
O, LizOfi is Mg (NO3) Z・611
20. and for comparison, Aj22C as feedstock for the zeta process.
h as a source (x AlzOz, Na as a NazO source
2GO,..., MgO of the NaOH stabilizer, and LizC (gco,...) and LiOH were used as the LizC source.
β″アルミナ種結晶としては、予め種結晶を添加しない
条件で作った粉末から結晶体を作成し、粗砕後、アセト
ン中でアルミナボールミルにより５〜１００時間粉砕し
て、平均粒径の異なる種結晶Ｂ、Ｃ，Ｄ、Ｅを得た。平
均粒径０．８μｍの種結晶Ａは、同じ粗砕物をアセトン
中で振動ミルにて２４時間粉砕して作成した。種結晶の
β″化率は８０％であった。β″化率の決定は、β相の
（１１０）ピーク強度Ｉ とβ″相の（０１，１１）ピ
ーク強度ｌβヶβ
の式を用いて算出した。For β″ alumina seed crystals, crystals are prepared from powder made in advance without adding seed crystals, coarsely crushed, and then crushed in acetone with an alumina ball mill for 5 to 100 hours to form seeds with different average particle sizes. Crystals B, C, D, and E were obtained. Seed crystal A with an average particle size of 0.8 μm was created by crushing the same coarsely crushed material in acetone with a vibration mill for 24 hours. β'' conversion rate of the seed crystal was 80%. The β″ conversion rate was calculated using the formula of the (110) peak intensity I of the β phase and the (01,11) peak intensity lβ−β of the β″ phase.
の式を用いて算出した。Calculated using the formula.
以下、更に具体的な実験例について述べる。More specific experimental examples will be described below.
まず、ＭｇＯを安定化剤として含む系についてはＮａｚ
Ｏ８，９重量％、Ｍｇ０ ２．１重量％、Ａ ｌ ｚＯ
ｓ ８９．０重量％となるように、またＬｉ、０を安
定化剤として含む系についてはＮａ、０ ９．０重量％
、ＬｉｚＯＯ，８重量％、Ａ ｌ ｚＯｓ ９０．２重
量％となるように、α−アルミナ、水酸化ナトリウム、
炭酸ナトリウム、硝酸マグネシウム、炭酸マグネシウム
、水酸化リチウム、炭酸リチウム等の原料を表１に示す
調合割合で調合した。First, regarding the system containing MgO as a stabilizer, Naz
O8.9% by weight, Mg0 2.1% by weight, Al zO
s 89.0% by weight, and for systems containing Li, 0 as a stabilizer, Na, 0 9.0% by weight.
, LizOO, 8% by weight, AlzOs 90.2% by weight, α-alumina, sodium hydroxide,
Raw materials such as sodium carbonate, magnesium nitrate, magnesium carbonate, lithium hydroxide, and lithium carbonate were prepared in the proportions shown in Table 1.
次いで、この混合粉末２００ｇ〜１００ｇと玉石（φ１
５ ７／！Ｊ３）１ｋｇに混合粉末に対して水分６０％
となるよう蒸留水を加え３１ポツト中で２０．５時間混
合粉砕し、その後各種粒径のβ″アルミナ種結晶を所定
量添加し、更に０．５時間混合した。種結晶は水と反応
し分解するため混合時間は２時間以下にすることが好ま
しい。次いで、４４μｍ以上の粗大粒子を除くために３
５０メツシユの篩でふるい分けし、スプレードライヤー
で乾燥、造粒し、１００メツシユ篩でふるい分けした。Next, 200g to 100g of this mixed powder and cobblestones (φ1
5 7/! J3) 60% moisture for 1kg of mixed powder
Distilled water was added and the mixture was mixed and pulverized for 20.5 hours in a 31 pot, and then a predetermined amount of β'' alumina seed crystals of various particle sizes were added and mixed for an additional 0.5 hours.The seed crystals reacted with water. The mixing time is preferably 2 hours or less to ensure decomposition.Then, the mixing time is preferably 3 hours or less to remove coarse particles of 44 μm or more.
The mixture was sieved through a 50-mesh sieve, dried with a spray dryer, granulated, and sieved through a 100-mesh sieve.
次いで、５０×５０×６の形状に、金型プレス（２００
ｋｇ／ｃｍ”）成形後、ラバープレス（１０００ｋｇ／
ｃｍ２） シ、表１に示す所定の焼成条件で焼成した。Next, a mold press (200
kg/cm") after molding, rubber press (1000 kg/cm")
cm2), and was fired under the predetermined firing conditions shown in Table 1.
焼成時のＮａ２Ｏ成分の蒸発を防ぐために、アルミする
つぼ中に各成形体と同し調合粉末を充填して埋焼とした
。In order to prevent evaporation of the Na2O component during firing, the same blended powder as that of each molded body was filled into an aluminum crucible and the molded body was buried.
また、焼成スケジュールとしては、１時間４００°Ｃで
１５００〜１６００’Ｃまで昇温し、最高温度で１０〜
６０分間保持し、１時間５００″Ｃの速さで１４００°
Ｃまで降温し、１４００°Ｃで５時間保持し、次いで１
時間に３００°Ｃの速さで降温した。In addition, the firing schedule was to raise the temperature to 1500-1600'C at 400°C for 1 hour, and then raise the temperature to 10-1600'C at the maximum temperature.
Hold for 60 minutes, 1400° at a speed of 500″C for 1 hour.
The temperature was lowered to 1400°C, held for 5 hours, and then 1
The temperature dropped at a rate of 300°C per hour.
比較例としてのゼータプロセスでの焼結体の作成は次の
手順で行なった。すなわち、’Ａｍ、 Ｃｅｒａｍ。A sintered body was prepared using the Zeta process as a comparative example using the following procedure. i.e. 'Am, Ceram.
Ｓｏｃ、 Ｂｕｌｌ、、 ５６． （２）、 ２０６．
（１９７７） ｊの”Ｓｉｎｔｅｒ−ｉｎｇ Ｐｒｏ
ｃｅｓｓｅｓ ａｎｄ ｌ１ｅａｔ Ｔｒｅａｔｍｅｎ
ｔ ５ｃｈｅｄｕｌｅｓｆｏｒ Ｃｏｎｄｕｃｔｉｖｅ
Ｌｉｔｈｉａ ５ｔａｂｉｌｉｚｅｄ β′−＾１
ｚｏｓ”に記載しであるように、２種類の混合物を作成
し、別々に仮焼して２つの化合物を作成後、それぞれ解
砕し、両者を調合してアセトン溶媒にてボットミル中で
２１時間粉砕し、できたスラリーにＰＶＢをバインダー
として添加後、スプレードライヤーで造粒した。第１の
混合物の組成は、Ｌｉ、０・５．５Ａ ｌ ２０３とし
、原料には炭酸リチウムとアルξすを用いた。第２の混
合物の組成は、Ａ ｆ ２０．・５Ａ ｌ ２０３ と
し原料には炭酸ナトリウムとアルξすを用いた。それぞ
れの混合物の仮焼温度は、１２６０°Ｃで仮焼時間は２
時間とした。Soc, Bull,, 56. (2), 206.
(1977) j's "Sinter-ing Pro"
cesses and treatmen
t 5 chedules for Conductive
Lithia 5 tabilized β'-^1
As described in "ZOS", two types of mixtures were created and calcined separately to create two compounds, then each was crushed, both were blended, and the two were mixed in an acetone solvent in a bot mill for 21 hours. After grinding and adding PVB as a binder to the resulting slurry, it was granulated using a spray dryer.The composition of the first mixture was Li, 0.5.5A l 203, and the raw materials were lithium carbonate and aluminum. The composition of the second mixture was A f 20.・5A l 203 and the raw materials were sodium carbonate and aluminum.The calcination temperature of each mixture was 1260°C, and the calcination time was 2
It was time.
以後の成形・焼成の条件は先に述べた水溶液噴霧乾燥法
と同じ条件とした。第２図にゼータプロセスでの製造の
フローチャートを示す。The subsequent molding and firing conditions were the same as those for the aqueous solution spray drying method described above. FIG. 2 shows a flowchart of production using the Zeta process.
上記各側について、β″化率、焼成収縮率、密度（焼結
体見掛密度）、四点曲げ強度、イオン伝導抵抗率を測定
した。結果を表１に示す。The β'' conversion rate, firing shrinkage rate, density (apparent density of sintered body), four-point bending strength, and ion conduction resistivity were measured for each of the above sides. The results are shown in Table 1.
第３図は種結晶の添加量と四点的強度の関係を示す。種
結晶を２％（重量％、以下同じ）以上、４５％以下添加
することにより、２５０ＭＰａ以上の強度の焼結体が得
られ、ゼータプロセスの焼結体と同等の強度となる。２
％未満の添加量では種結晶の量が不足して、異常粒成長
が起こり、強度劣化が生じているものと考えられる。種
結晶の添加量が２％以上、４５％以下では種結晶の量が
適切なため、全体に均一な粒成長が起こり、均質な微構
造となって高強度の焼結体となる。種結晶の添加量が４
５％を越えると、焼結性が低下して、低密度の焼結体と
なり強度が低値を示すようになる。FIG. 3 shows the relationship between the amount of seed crystal added and the strength at four points. By adding 2% (wt%) or more and 45% or less of seed crystals, a sintered body with a strength of 250 MPa or more can be obtained, which is equivalent to the strength of the sintered body of the Zeta process. 2
It is thought that if the amount added is less than %, the amount of seed crystals becomes insufficient, causing abnormal grain growth and deterioration of strength. When the amount of seed crystals added is 2% or more and 45% or less, the amount of seed crystals is appropriate, so that uniform grain growth occurs throughout, resulting in a homogeneous microstructure and a high-strength sintered body. The amount of seed crystal added is 4
When it exceeds 5%, the sinterability decreases, resulting in a low-density sintered body with low strength.
第４図に種結晶添加量とβ″化率の関係を示す。FIG. 4 shows the relationship between the amount of seed crystals added and the β'' conversion rate.
β″アルξす焼結体を製造する時に重要な点は、Ｎａイ
オン伝導抵抗率の低いβ″相を充分に生成することであ
る。第４図から分かるように、結晶相の主成分がβ″相
からなる種結晶を添加することは、β”化率を向上させ
るために有効であり、２％以上添加することで、９４％
以上のβ”化率のβ″アルミナ結晶体を製造することが
できる。An important point when producing a sintered body containing β'' is to sufficiently generate a β'' phase with low Na ion conduction resistivity. As can be seen from Fig. 4, adding seed crystals whose main crystalline component is the β'' phase is effective for improving the β'' conversion rate, and by adding 2% or more, the seed crystal can reach 94%.
It is possible to produce a β″ alumina crystal with the above β″ conversion rate.
第５図に種結晶添加量と３００°ＣでのＮａイオン伝導
抵抗率の関係を示す。この図より種結晶を２％以上添加
することにより、３００″ＣでのＮａイオン伝導抵抗率
が５Ω・ｃｍ以下となり、ナトリウム−硫黄電池用に好
適のβ″アルミナ焼結体が得られることが分る。FIG. 5 shows the relationship between the amount of seed crystal added and the Na ion conduction resistivity at 300°C. From this figure, it can be seen that by adding 2% or more of seed crystals, the Na ion conduction resistivity at 300"C becomes 5Ωcm or less, and a β" alumina sintered body suitable for sodium-sulfur batteries can be obtained. I understand.
第６図にβ″化率と３００″ＣでのＮａイオン伝導抵抗
率の関係を示す。この図よりβ″化率の向上がＮａイオ
ン伝導抵抗率の低減に極めて有効であることが分る。ま
た実施例１〜８と比較例６，７の比較により、ナトリウ
ム源に水溶性の水酸化ナトリウムを用いた時に本発明の
製造方法がβ″化率を向上させるために有効であること
が分る。また水溶性の原料を用いない場合、焼結性も低
下して低強度の焼結体しか得られない。FIG. 6 shows the relationship between the β'' conversion rate and the Na ion conduction resistivity at 300''C. From this figure, it can be seen that improving the β'' rate is extremely effective in reducing the Na ion conduction resistivity.Also, by comparing Examples 1 to 8 and Comparative Examples 6 and 7, it is found that the sodium source contains water-soluble water. It can be seen that the production method of the present invention is effective for improving the β'' conversion rate when sodium oxide is used. Furthermore, when water-soluble raw materials are not used, sinterability is also reduced and only a sintered body with low strength can be obtained.
さらに第７図に焼成温度と焼結体密度の関係を示す。ゼ
ータプロセスに対して本発明の製造法では、１５４０”
Ｃから１６００″Ｃの広い範囲にわたって特性の安定し
た焼結体を得ることができる。またキープ時間について
も実施例１〜８から分るようにゼ−タプロセスのように
１０分以下の短時間でなくとも、キープ時間を伸ばして
も粒成長による特性の劣化が認められない。このため、
ゼータプロセスのように焼成条件を非常に厳密に制御す
る必要がないため、製造上大いなる利点がある。Further, FIG. 7 shows the relationship between firing temperature and sintered body density. In the production method of the present invention for the Zeta process, 1540"
It is possible to obtain a sintered body with stable properties over a wide range from C to 1600"C. Also, as seen from Examples 1 to 8, the holding time is short, 10 minutes or less, like the Zeta process. Even if it is not, no deterioration of properties due to grain growth is observed even if the holding time is extended.
Unlike the Zeta process, it is not necessary to control the firing conditions very strictly, so there is a great advantage in manufacturing.
また第８図に種結晶添加量１０重量％の場合の、四点曲
げ強度の種結晶平均粒径依存性を示す。種結晶の平均粒
径が１μｍ未満では、種結晶の大きさが小さ過ぎるため
種結晶が周囲の組織に吸収されてしまい、有効に働かず
、粗大粒の成長が起って強度が劣化し、２５０ ＭＰａ
以下ととなる。また種結晶の平均粒径が９μｍを超える
と、種結晶の焼結性が低下するため、得られる焼結体の
強度が劣化し、２５０ ＭＰａ以下となる。Furthermore, FIG. 8 shows the dependence of the four-point bending strength on the average grain size of the seed crystals when the amount of seed crystals added is 10% by weight. If the average grain size of the seed crystal is less than 1 μm, the seed crystal is too small and will be absorbed into the surrounding tissue, and will not work effectively, resulting in the growth of coarse grains and deterioration of strength. 250MPa
The following is true. Furthermore, if the average particle size of the seed crystal exceeds 9 μm, the sinterability of the seed crystal decreases, and the strength of the obtained sintered body deteriorates to 250 MPa or less.
また種結晶中に４４μｍ以上の粗大な種結晶が含まれて
いても、焼結体の強度劣化の原因となるため、種結晶の
添加後、３２５メツシュ以上の篩で篩分けしてこのよう
な粗大種結晶を除去しておくことが望ましい。In addition, even if the seed crystal contains coarse seed crystals of 44 μm or more, it will cause the strength of the sintered body to deteriorate. It is desirable to remove coarse seed crystals.
（発明の効果）
以上説明した通り、本発明によれば次の効果が奏せられ
る。(Effects of the Invention) As explained above, according to the present invention, the following effects can be achieved.
β″アルミナ焼結体の製造法として公知のゼータプロセ
スでは原料調製時に、２種類の混合物に対して仮焼、粉
砕が余分に必要であり、また最終調合物の粉砕時に有機
溶媒を用いる必要がある。The Zeta process, which is a well-known method for producing β″ alumina sintered bodies, requires extra calcination and pulverization of two types of mixtures during raw material preparation, and also requires the use of an organic solvent when pulverizing the final mixture. be.
これに対して水溶液噴霧乾燥法では混合粉砕時に水が使
用でき、混合粉砕工程も１回で澄む低コストの製造法で
あるが、β″化率が低いためイオン伝導抵抗率が高く、
低強度であるという問題があった。On the other hand, the aqueous solution spray drying method allows water to be used during mixing and pulverization, and is a low-cost manufacturing method that clears the mixture and pulverization process in just one time.
There was a problem of low strength.
この水溶液噴霧乾燥法に本発明の製造法により、定めら
れた平均粒径の結晶相の主成分がβ″相からなる種結晶
を所定量添加することにより、β″化率が向上してイオ
ン伝導抵抗率が低下し、しかも均一な粒成長が生じるた
め、結晶体強度も向上してナトリウム−硫黄電池等に好
適なβ″アルミナ焼結体が得られる。さらに焼成温度幅
も、ゼータプロセスに比べて広いため、ゼータプロセス
の急速昇温、高温短時間保持が不要となり、製造上大な
る利点がある。By adding a predetermined amount of seed crystals having a predetermined average particle size and the main component of the crystalline phase being the β″ phase to this aqueous solution spray drying method, the β″ conversion rate is improved and the ionization rate is improved. Since the conductive resistivity is reduced and uniform grain growth occurs, the crystal strength is improved and a β″ alumina sintered body suitable for sodium-sulfur batteries etc. can be obtained.Furthermore, the firing temperature range is also similar to that of the zeta process. Since it is relatively wide, there is no need for rapid temperature rise or short-time holding at high temperature in the zeta process, which is a great advantage in manufacturing.
第１図は本発明の製造方法を示すフローチャート、
第２図は従来のゼータプロセス示すフローチャート、
第３図は四点曲げ強度とβ″アルミナ種結晶の添加量と
の関係を示すグラフ、
第４図はβ″化率とβ″アルミナ種結晶の添加量との関
係を示すグラフ１
、第５図ば３００’Ｃでのナトリウムイオン伝導抵抗率
とβ″種結晶の添加量との関係を示すグラフ、第６図は
３００°ＣでのＮａイオン伝導抵抗率とβ″化率との関
係を示すグラフ、
第７図は本発明の実施例とゼータプロセスとにおける焼
結体密度と焼結温度との関係を示すグラフ、
第８図は四点曲げ強度と種結晶平均粒径との関係を示す
グラフである。
第１図
第２図
゛（ソ＠−２
第５図
２
０
２０ ３０ １１０
＃Ｊ！＆ネｈ糧（重量％）
０
５００
第７図
ｆ５４０１５５０
煙戚温贋（Ｃ）
ｌσθＯFig. 1 is a flowchart showing the manufacturing method of the present invention, Fig. 2 is a flowchart showing the conventional zeta process, Fig. 3 is a graph showing the relationship between four-point bending strength and the amount of β'' alumina seed crystal added, and Fig. 4 Figure 1 shows the relationship between the β'' conversion rate and the amount of β'' alumina seed crystal added, and Figure 5 shows the relationship between the sodium ion conduction resistivity at 300'C and the amount of β'' seed crystal added. Graph, Figure 6 is a graph showing the relationship between Na ion conduction resistivity and β'' conversion rate at 300°C, Figure 7 is the sintered body density and sintering temperature in the example of the present invention and the Zeta process. Figure 8 is a graph showing the relationship between the four-point bending strength and the average grain size of the seed crystal. #J! & Neh food (weight %) 0 500 Fig. 7 f5401550 Smoke related warm fake (C) lσθO
Claims (1)
て混合粉砕した後、噴霧乾燥して造粒し、次いで成形、
焼成を行うβ″アルミナ焼結体の製造方法において、前
記混合粉砕後に結晶相の主成分がβ″アルミナ相からな
りかつ平均粒径が１μｍ以上、９μｍ以下のβ″アルミ
ナ種結晶を２重量％以上、４５重量％以下添加混合する
ことを特徴とするβ″アルミナ焼結体の製造方法。1. After mixing and pulverizing water-soluble alkaline raw materials and alumina raw materials using water, they are spray-dried and granulated, then molded,
In the method for producing a β″ alumina sintered body by firing, after the mixing and pulverization, 2% by weight of β″ alumina seed crystals whose main component is a β″ alumina phase and whose average particle size is 1 μm or more and 9 μm or less is added. A method for producing a β'' alumina sintered body, characterized in that the above is added and mixed in an amount of 45% by weight or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1180593A JPH0696466B2 (en) | 1989-07-14 | 1989-07-14 | Method for manufacturing β "alumina sintered body |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1180593A JPH0696466B2 (en) | 1989-07-14 | 1989-07-14 | Method for manufacturing β "alumina sintered body |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0345554A true JPH0345554A (en) | 1991-02-27 |
| JPH0696466B2 JPH0696466B2 (en) | 1994-11-30 |
Family
ID=16085977
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1180593A Expired - Fee Related JPH0696466B2 (en) | 1989-07-14 | 1989-07-14 | Method for manufacturing β "alumina sintered body |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0696466B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0547412A (en) * | 1991-08-12 | 1993-02-26 | Ngk Insulators Ltd | Beta-alumina solid electrolyte |
| JPH07272749A (en) * | 1994-03-29 | 1995-10-20 | Ngk Insulators Ltd | Betaalumina solid electrolyte and its manufacture |
| KR101337407B1 (en) * | 2012-03-15 | 2013-12-06 | 건국대학교 산학협력단 | Fabrication of beta-alumina solid electrolyte with addition of beta-alumina seeds in spray-drying process and the secondary battery using it |
-
1989
- 1989-07-14 JP JP1180593A patent/JPH0696466B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0547412A (en) * | 1991-08-12 | 1993-02-26 | Ngk Insulators Ltd | Beta-alumina solid electrolyte |
| JPH07272749A (en) * | 1994-03-29 | 1995-10-20 | Ngk Insulators Ltd | Betaalumina solid electrolyte and its manufacture |
| KR101337407B1 (en) * | 2012-03-15 | 2013-12-06 | 건국대학교 산학협력단 | Fabrication of beta-alumina solid electrolyte with addition of beta-alumina seeds in spray-drying process and the secondary battery using it |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0696466B2 (en) | 1994-11-30 |
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