JP2944142B2 - Lithium ion conductive composite sintered body - Google Patents
Lithium ion conductive composite sintered bodyInfo
- Publication number
- JP2944142B2 JP2944142B2 JP2110887A JP11088790A JP2944142B2 JP 2944142 B2 JP2944142 B2 JP 2944142B2 JP 2110887 A JP2110887 A JP 2110887A JP 11088790 A JP11088790 A JP 11088790A JP 2944142 B2 JP2944142 B2 JP 2944142B2
- Authority
- JP
- Japan
- Prior art keywords
- sintered body
- conductivity
- lithium
- tio
- lithium ion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 title claims description 21
- 229910001416 lithium ion Inorganic materials 0.000 title claims description 21
- 239000002131 composite material Substances 0.000 title claims description 8
- 229910018068 Li 2 O Inorganic materials 0.000 claims description 39
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims description 37
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 20
- 239000013078 crystal Substances 0.000 description 23
- 229910010413 TiO 2 Inorganic materials 0.000 description 21
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 11
- 229910052744 lithium Inorganic materials 0.000 description 11
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 10
- 238000002441 X-ray diffraction Methods 0.000 description 7
- 150000002500 ions Chemical class 0.000 description 7
- 230000032258 transport Effects 0.000 description 7
- 238000005259 measurement Methods 0.000 description 6
- 239000002994 raw material Substances 0.000 description 6
- 239000000463 material Substances 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 229910052697 platinum Inorganic materials 0.000 description 5
- 239000000919 ceramic Substances 0.000 description 4
- 239000010416 ion conductor Substances 0.000 description 4
- IIPYXGDZVMZOAP-UHFFFAOYSA-N lithium nitrate Chemical compound [Li+].[O-][N+]([O-])=O IIPYXGDZVMZOAP-UHFFFAOYSA-N 0.000 description 4
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 239000004020 conductor Substances 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
- 238000005245 sintering Methods 0.000 description 3
- 239000007784 solid electrolyte Substances 0.000 description 3
- 238000012790 confirmation Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000037427 ion transport Effects 0.000 description 2
- 238000005372 isotope separation Methods 0.000 description 2
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 description 2
- HSZCZNFXUDYRKD-UHFFFAOYSA-M lithium iodide Chemical compound [Li+].[I-] HSZCZNFXUDYRKD-UHFFFAOYSA-M 0.000 description 2
- 230000010287 polarization Effects 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 229910000505 Al2TiO5 Inorganic materials 0.000 description 1
- 229910013553 LiNO Inorganic materials 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000000280 densification Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 description 1
- 229910052808 lithium carbonate Inorganic materials 0.000 description 1
- 229910003002 lithium salt Inorganic materials 0.000 description 1
- 159000000002 lithium salts Chemical class 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 238000013001 point bending Methods 0.000 description 1
- AABBHSMFGKYLKE-SNAWJCMRSA-N propan-2-yl (e)-but-2-enoate Chemical compound C\C=C\C(=O)OC(C)C AABBHSMFGKYLKE-SNAWJCMRSA-N 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000007725 thermal activation Methods 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
- BHZCMUVGYXEBMY-UHFFFAOYSA-N trilithium;azanide Chemical compound [Li+].[Li+].[Li+].[NH2-] BHZCMUVGYXEBMY-UHFFFAOYSA-N 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000012982 x-ray structure analysis Methods 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
- Secondary Cells (AREA)
- Compositions Of Oxide Ceramics (AREA)
- Conductive Materials (AREA)
- Primary Cells (AREA)
Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は、リチウムの同位体の分離などに使用できる
固体電解質、または固体電池やイオンセンサーの材料と
なる物質に関する。Description: TECHNICAL FIELD The present invention relates to a solid electrolyte which can be used for separation of isotopes of lithium or the like, or a substance which is used as a material for a solid battery or an ion sensor.
［従来の技術］ 従来、リチウムイオン導電体としては、リチウム電池
の固体電滑質としてヨウ化リチウムが用いられており、
チッ化リチウム系のものについての提案もある（特開昭
56−128580号）。しかし、これらは常温ではある程度の
リチウム導電性を示すが、分解温度が低いので、高温で
使用することはできない。リチウム同位体の分離には30
0℃以上の高温での使用に耐えるものでなければなら
ず、セラミックス系でリチウム導電性を有するものが期
待されており、一部提案もなされている（特開昭56−16
4015号、57−200222号）。[Prior Art] Conventionally, lithium iodide has been used as a lithium ion conductor as a solid electrolyte of a lithium battery.
There is also a proposal for a lithium nitride-based material (see
No. 56-128580). However, although they exhibit some lithium conductivity at room temperature, they cannot be used at high temperatures because of their low decomposition temperatures. 30 for lithium isotope separation
It must be able to withstand use at a high temperature of 0 ° C. or higher, and ceramics having lithium conductivity are expected, and some proposals have been made (Japanese Patent Application Laid-Open No. 56-16 / 1981).
No. 4015, 57-200222).
［発明が解決しようとする課題］ 従来のリチウム導電体は、常温ではリチウム導電性を
示しても高温においては使用できなかったり、またセラ
ミックス系のものでも強度において不十分であって、現
実には高温で使用できるリチウム導電体が供給されてい
ないのが実状である。[Problems to be Solved by the Invention] Conventional lithium conductors cannot be used at high temperatures even if they exhibit lithium conductivity at room temperature, or have insufficient strength even with ceramics. In fact, no lithium conductor that can be used at high temperatures is supplied.
本発明は、従来のリチウムイオン導電体の欠点を解消
し、高温においても安定で、導電率が高く、しかも十分
な強度を有し、材料の信頼性の上でも優れたリチウムイ
オン導電性セラミックス焼結体を提供することを目的と
してなされたものである。The present invention eliminates the disadvantages of conventional lithium ion conductors, is stable at high temperatures, has high conductivity, has sufficient strength, and has excellent reliability in material, and is excellent in material reliability. The purpose is to provide union.
［課題を解決するための手段］ Li2Oを含むリチウムイオン導電体としては、Li2O・3T
iO2（ラムスデライト型構造）や2Li2O・5TiO2の組成の
ものが知られているが、これらは強度が著しく小さいた
めに実用に供することができない。[Means for Solving the Problems] As the lithium ion conductors including a Li 2 O, Li 2 O · 3T
iO 2 but having composition of (ramsdellite structure) or 2Li 2 O · 5TiO 2 are known, it can not be practically used because the strength is remarkably low.
本発明者は、Li2Oを含む各種の組成物を検討した結
果、Li2O−Al2O3−TiO2の系において、Li2O・Al2O3・4T
iO2とルチル（TiO2）の２相の結晶相を含む焼結体がリ
チウムイオン導電性と強度を合わせ持つことを見出し、
本発明に到達したものである。The present inventor studied various compositions containing Li 2 O, and found that in the system of Li 2 O-Al 2 O 3 -TiO 2 , Li 2 OAl 2 O 3 .4T
They found that a sintered body containing two crystal phases of iO 2 and rutile (TiO 2 ) had both lithium ion conductivity and strength,
The present invention has been reached.
すなわち本発明は、Li2O・Al2O3・4TiO2とルチル（Ti
O2）の２相の結晶相を含むことを特徴とするリチウムイ
オン導電性複合焼結体に関する。That is, the present invention, Li 2 O · Al 2 O 3 · 4TiO 2 and rutile (Ti
The present invention relates to a lithium ion conductive composite sintered body characterized by containing two crystal phases of O 2 ).
本発明者の研究によれば、1100℃以上での焼結品で
は、一般式Li2Al2xTiyO(1+3x+2y)で示されるLi2OとAl2O
3とTiO2からなる結晶構造のものは、Li2Al2Ti4O12（上
記一般式において、ｘ＝１、ｙ＝４）のもの、すなわ
ち、Li2O・Al2O3・4TiO2しか存在しないようである。Li
2O・Al2O3・4TiO2の結晶については、その構造が具体的
にどのようなものかは明確でないが、この結晶相につい
ては文献による報告もあり（Journal of the American
Ceramic Society Vol.43,No.12,PP.61〜614（196
0））、またＸ線回折で同定することができる。According to the study of the present inventors, in a sintered product at 1100 ° C. or higher, Li 2 O and Al 2 O represented by the general formula Li 2 Al 2x Ti y O (1 + 3x + 2y)
3 and those of the crystal structure consisting of TiO 2, (in the general formula, x = 1, y = 4 ) Li 2 Al 2 Ti 4 O 12 ones, i.e., Li 2 O · Al 2 O 3 · 4TiO 2 Seems to exist only. Li
For the 2 O · Al 2 O 3 · 4TiO 2 crystal, but its structure or is not clear what specific things, this crystal phase is also reported by the literature (Journal of the American
Ceramic Society Vol.43, No.12, PP.61-614 (196
0)), and can be identified by X-ray diffraction.
Li2O・Al2O3・4TiO2とルチル（TiO2）の２相の結晶か
らなる焼結体は、Li2O:Al2O3:TiO2の比が1:1:4よりTiO2
を多く含むように配合した原料を、1100℃以上の温度で
緻密に焼結することにより作製することができる。例え
ば、アルミナ（Al2O3）粉体とチタニア（TiO2）粉体を
混合し、これにリチウム塩（硝酸リチウム、塩化リチウ
ム、炭酸リチウム、水酸化リチウムなど）を添加して、
チタン酸アルミニウムを生成しない1300℃以下の温度
で、かつ十分に緻密化が進行する1100℃以上の温度で焼
成することにより製造することができる。A sintered body composed of a two-phase crystal of Li 2 O.Al 2 O 3 .4TiO 2 and rutile (TiO 2 ) has a ratio of Li 2 O: Al 2 O 3 : TiO 2 of 1: 1: 4. Two
Can be produced by densely sintering a raw material blended so as to contain a large amount at a temperature of 1100 ° C. or higher. For example, alumina (Al 2 O 3 ) powder and titania (TiO 2 ) powder are mixed, and a lithium salt (lithium nitrate, lithium chloride, lithium carbonate, lithium hydroxide, etc.) is added thereto,
It can be manufactured by firing at a temperature of 1300 ° C. or less at which aluminum titanate is not generated and at a temperature of 1100 ° C. or more at which densification proceeds sufficiently.
本発明者の研究によれば、例えば、原料として、Al2O
3とTiO2とLiNO3をLi2O:Al2O3:TiO2の比が1:1:4よりもTi
O2が多い組成となるように配合して焼結した場合には、
600℃までに窒素酸化物が飛び、800℃で2Li2O・5TiO2と
これに加えてアナターゼ（TiO2）が生成し、アナターゼ
の一部はルチル（TiO2）となる。1000℃では、Li2O・3T
iO2とルチルの２相構造となるが、1100℃以上では、Li2
O・Al2O3・4TiO2の他にTiO2（ルチル）が含まれる２層
構造となる。According to the study of the present inventors, for example, Al 2 O
3 and TiO 2 and LiNO 3 Li 2 O: Al 2 O 3: The ratio of TiO 2 is 1: 1: Ti than 4
Formulated as O 2 is frequently composition when sintered is
Fly nitrogen oxides to 600 ° C., in addition to the 2Li 2 O · 5TiO 2 at 800 ° C. anatase (TiO 2) is produced, some of anatase is rutile (TiO 2). At 1000 ° C, Li 2 O ・ 3T
iO 2 and becomes a two-phase structure of rutile, in 1100 ° C. or more, Li 2
It has a two-layer structure containing TiO 2 (rutile) in addition to O.Al 2 O 3 .4TiO 2 .
実験によれば、Li2O:Al2O3:TiO2の配合比が1:1:4より
もTiO2のみ多い組成物の1100〜1300℃での焼結品は、上
記２相構造以外はとらない。このものはリチウムイオン
導電性に加えて優れて強度を有する焼結体となる。According to the experiment, the sintered product at 1100-1300 ° C. of the composition with Li 2 O: Al 2 O 3 : TiO 2 compounding ratio of only TiO 2 more than 1: 1: 4 is other than the above two-phase structure. Do not take. This is a sintered body having excellent strength in addition to lithium ion conductivity.
リチウムイオン電導を可能としているのは、Li2O・Al
2O3・4TiO2であり、TiO2の量があまり多くなると、電子
電導の割合が多くなってしまうので、実用上十分なリチ
ウムイオン電導のためには、Li2O・Al2O3・4TiO2結晶１
モルに対してルチルが４モルよりより少なく、すなわち
焼結体全体の重量に対するLi2O・Al2O3・4TiO2結晶の含
有量が58重量％以上となるようにするのが望ましい。ま
た、TiO2は強度に寄与していると考えられ、十分な強度
を得るためには、Li2O・Al2O3・4TiO2結晶１モルに対し
てルチルが0.6モルより多く、すなわち、焼結体全体の
重量に対するLi2O・Al2O3・4TiO2結晶の含有量が90重量
％以下となるようにするのが望ましい。Li 2 O ・ Al enables lithium ion conduction
2 O 3 · 4TiO 2 , if the amount of TiO 2 is too large, the proportion of electron conduction will increase, so for practically sufficient lithium ion conduction, Li 2 O · Al 2 O 3 · 4TiO 2 crystal 1
Less than than rutile 4 mol per mol, i.e. to as the content of Li 2 O · Al 2 O 3 · 4TiO 2 crystals based on the total weight of the sintered body is 58 wt% or more. Further, TiO 2 is believed to contribute to the strength, in order to obtain sufficient strength, Li 2 O · Al 2 O 3 · 4TiO 2 rutile more than 0.6 mole with respect to the crystal 1 mole, i.e., It is desirable that the content of Li 2 O.Al 2 O 3 .4TiO 2 crystals be 90% by weight or less based on the weight of the entire sintered body.
Al2O3の配合比も20％程度の範囲内での変動は可能で
あり、従って、原料の配合は、焼結後にLi2O:Al2O3:TiO
2がモル比で1:0.8〜1.2:4.6〜８となるように行う。こ
の比率の範囲においてAl2O3のモル比が１より大きい場
合には、α相あるいはγ相アルミナがわずかに形成され
る可能性があり、また、Al2O3のモル比が１より小さい
場合には、Li2Oが過剰となり、わずかに別の結晶のもの
が形成される可能性がある。このような別の結晶の存在
は微量であれば、焼結体の性能に与える影響は少ない
が、好ましいものではないので、原料の配合は、焼結体
中、Li2O:Al2O3:TiO2のモル比が1:1:4.6〜８となるよう
にするのが望ましく、特に望ましくは、1:1:6付近であ
る。The mixing ratio of Al 2 O 3 can also be varied within the range of about 20%. Therefore, the mixing of the raw materials is performed after the sintering of Li 2 O: Al 2 O 3 : TiO 2.
The reaction is carried out so that the molar ratio of 2 is 1: 0.8 to 1.2: 4.6 to 8. When the molar ratio of Al 2 O 3 is greater than 1 in this ratio range, α-phase or γ-phase alumina may be slightly formed, and the molar ratio of Al 2 O 3 is smaller than 1. In some cases, Li 2 O may be in excess and slightly different crystalline forms may be formed. If the presence of such another crystal is a trace amount, the effect on the performance of the sintered body is small, but it is not preferable, so the mixing of the raw materials is such that Li 2 O: Al 2 O 3 : TiO 2 is preferably in a molar ratio of 1: 1: 4.6 to 8, particularly preferably in the vicinity of 1: 1: 6.
1:1:4よりもTiO2が多く、かつLi2Oがかなり過剰な組
成のもの、例えばLi2O:Al2O3:TiO2のモル比が2:1:6の配
合比のものは、1100℃以上の焼結において、Li2O・Al2O
3・4TiO2の他にLi2O・3TiO2（ラムスデライト型）を含
む構造となる。この２相構造では、リチウム導電性を示
すが、強度がないので、リチウム導電体として実用性が
ない。TiO 2 more than 1: 1: 4, and a composition of Li 2 O considerably excess, for example, a molar ratio of Li 2 O: Al 2 O 3 : TiO 2 is 2: 1: 6 Is Li 2 O ・ Al 2 O
In addition to 3 · 4TiO 2 a structure containing Li 2 O · 3TiO 2 (ramsdellite). This two-phase structure shows lithium conductivity, but lacks strength and is not practical as a lithium conductor.
上記よりもさらにLi2Oのモル比が多くなると、Li2O・
TiO2、2Li2O・5TiO2、2Li2O・Al2O3などが形成されるよ
うになり、Li2O・Al2O3・4TiO2結晶は形成されない。If the molar ratio of Li 2 O is further increased than the above, Li 2 O
Become like TiO 2, 2Li 2 O · 5TiO 2, 2Li 2 O · Al 2 O 3 is formed, Li 2 O · Al 2 O 3 · 4TiO 2 crystals are formed.
焼結体の評価 本発明において焼結体のイオン電導度はインピーダン
スアナライザーを用いて、測定温度、周波数を変化させ
て、交流イオン電導度を測定することにより行った。他
のデータは以下のようにして確認あるいは測定した。Evaluation of Sintered Body In the present invention, the ion conductivity of the sintered body was measured by changing the measurement temperature and frequency and measuring the AC ion conductivity using an impedance analyzer. Other data were confirmed or measured as follows.
（リチウムイオン導電種の確認） イオン導電種がリチウムイオンであることの確認は次
のようにして行った。リチウムイオンは白金と反応して
Li2PtO3という化合物を作ることが知られている。電極
として白金を用いて、両電極間に直流電圧を印加して分
極を起こさせた場合、負極側にLi2PtO3が生成していれ
ば、リチウムイオンが導電種として働いていると確認で
きるので、直流電圧を印加して一定時間経過後の正負の
電極についてＸ線構造解析を行うとにより行った。(Confirmation of Lithium Ion Conductive Species) Confirmation that the ionic conductive species was lithium ion was performed as follows. Lithium ion reacts with platinum
It is known to make a compound called Li 2 PtO 3 . When platinum is used as an electrode and a DC voltage is applied between both electrodes to cause polarization, if Li 2 PtO 3 is generated on the negative electrode side, it can be confirmed that lithium ions are working as a conductive species Therefore, X-ray structure analysis was performed on the positive and negative electrodes after a certain period of time from the application of a DC voltage.
（輸率の計算） 輸率とは全電導度（イオン電導度＋電子電導度）に対
するイオン電導度の比であり、従ってイオン電導度のみ
であれば輸率は１となる。イオン電導と電子電導の混合
電子体であれば輸率は１より小さくなる。そして、混合
電子体の場合、交流回路で測定した電導度は、イオン電
導度σｉと電子電導度σｅとの混合電導度σｔ＝σｉ＋
σｅである。直流回路を用いると分極を生じるので、イ
オン電導度σｉは時間がたつにつれて０に近付き、理論
的には時間が∞のときの電導度がσｅとなる。本発明の
系では、30分程度経過すると電導度が一定になったの
で、この時の電導度の値をσｅとして、以下の式で輸率
を計算した。(Calculation of the transport number) The transport number is a ratio of the ionic conductivity to the total electrical conductivity (ionic conductivity + electron electrical conductivity). Therefore, if only the ionic conductivity is used, the transport number is 1. In the case of a mixed electron body of ion conduction and electron conduction, the transport number is smaller than 1. In the case of a mixed electronic body, the conductivity measured by the AC circuit is a mixed conductivity σt = σi + of the ionic conductivity σi and the electron conductivity σe.
σe. Since polarization occurs when a DC circuit is used, the ionic conductivity σi approaches 0 with time, and theoretically the conductivity when the time is ∞ becomes σe. In the system of the present invention, the conductivity became constant after about 30 minutes, and the transport number was calculated by the following equation, using the value of the conductivity at this time as σe.
輸率ｔ＝σi/（σｉ＋σｅ）＝（σｔ−σｅ）／σｔ ＝１−Rt/Re ……（１） ここで、Rtは、インピーダンスアナライザーで測定し
た交流回路抵抗値であり、Reは、直流回路につなぎ30分
経過後一定となった時の抵抗値である。Transport number t = σi / (σi + σe) = (σt−σe) / σt = 1−Rt / Re (1) where Rt is an AC circuit resistance measured by an impedance analyzer, and Re is DC It is the resistance value when it becomes constant after 30 minutes after connecting to the circuit.
［作用］ 本発明の複合焼結体は、Li2O・Al2O3・4TiO2の結晶と
ルチルの結晶の２相からなり、優れたリチウムイオン導
電性と強度を示すものである。これは、Li2O・Al2O3・4
TiO2結晶がその内部において、結晶中のリチウムイオン
の移動を可能としており、これによりリチウムイオン導
電性を示すものと解される。[Operation] composite sintered body of the present invention, a two-phase of Li 2 O · Al 2 O 3 of · 4TiO 2 crystal and rutile crystal, exhibits excellent lithium ion conductivity and strength. This is Li 2 O ・ Al 2 O 3・ 4
It can be understood that the TiO 2 crystal allows lithium ions to move inside the crystal, thereby exhibiting lithium ion conductivity.
また、強度に関しては、本発明の複合焼結体は上記Li
2O・Al2O3・4TiO2とルチルとの組み合わせが強度を与え
ている。これに対して、Li2O・Al2O3・4TiO2結晶を含む
ものであっても、Li2O・Al2O3・4TiO2結晶単独のもの或
いはこれとルチル以外の結晶、例えばLi2O・3TiO2との
組み合わせのものは本発明品に比べると強度が1/10以下
程度と著しく小さい。Regarding the strength, the composite sintered body of the present invention
Combination of 2 O · Al 2 O 3 · 4TiO 2 and rutile has given strength. In contrast, Li 2 O · Al 2 O 3 · 4TiO also comprise 2 crystal, Li 2 O · Al 2 O 3 · 4TiO 2 crystals alone ones or this and the crystal other than rutile, such as Li The combination with 2 O · 3TiO 2 has a remarkably low strength of about 1/10 or less as compared with the product of the present invention.
本発明にかかる複合焼結体は、Li2O・Al2O3・4TiO2結
晶とルチル結晶との組み合わせにより、高温での使用に
耐えるリチウムイオン導電体が提供される。The composite sintered body according to the present invention provides a lithium ion conductor that can withstand use at a high temperature by a combination of Li 2 O.Al 2 O 3 .4TiO 2 crystal and rutile crystal.
［実施例１］ 原料として、それぞれ99.9％以上の純度のチタニア
（TiO2）、アルミナ（Al2O3）及び硝酸リチウム（LiN
O3）を、焼結体におけるLi2O:Al2O3:TiO2のモル比が1:
1:6となるように配合し、水に溶解した。これをボール
ミルで十分混合したのち、乾燥器（120℃）で乾燥させ
た。次に800℃で１時間仮焼し、粉砕、成形の後、1200
℃で２時間焼成して緻密な焼結体を得た。Example 1 As raw materials, titania (TiO 2 ), alumina (Al 2 O 3 ), and lithium nitrate (LiN
O 3 ), the molar ratio of Li 2 O: Al 2 O 3 : TiO 2 in the sintered body is 1:
1: 6 and dissolved in water. This was sufficiently mixed with a ball mill and then dried in a drier (120 ° C.). Next, it is calcined at 800 ° C for 1 hour, pulverized, molded,
C. for 2 hours to obtain a dense sintered body.
この焼結体の結晶構造をＸ線回折により調べたとこ
ろ、第１図のような回折図となり、△で示したLi2Al2Ti
O4O12（Li2O・Al2O3・4TiO2）のピーク、○で示したTiO
2（ルチル）のピークにより、これらの２相からなる複
合焼結体となっていることが確認された。When the crystal structure of this sintered body was examined by X-ray diffraction, a diffraction pattern as shown in FIG. 1 was obtained, and the Li 2 Al 2 Ti
O 4 O 12 (Li 2 O ・ Al 2 O 3・ 4TiO 2 ) peak, TiO indicated by ○
The peak of 2 (rutile) confirmed that the composite sintered body was composed of these two phases.
インピーダンスアナライザー（横河ヒューレットパッ
カード社製、LF−4192A）を用いて、上記の焼結体の交
流イオン電導度を測定した。なお、測定試料としては、
直径20mm、厚さ1mmのペレットを用い、電極は白金ペー
ストを用い900℃で20分焼成しその上に白金の網をかぶ
せ再焼成し、それに白金線をからまてその線を測定装置
まで延ばした。The AC ion conductivity of the sintered body was measured using an impedance analyzer (LF-4192A, manufactured by Yokogawa Hewlett-Packard Company). In addition, as a measurement sample,
Using pellets with a diameter of 20 mm and a thickness of 1 mm, the electrodes are baked at 900 ° C for 20 minutes using platinum paste, covered with a platinum net and fired again, and then wrapped with platinum wires and extended to the measuring device. Was.
まず、20℃から800℃まで上げ下げを繰り返し安定性
について評価したところ、ほとんど劣化が見られず、温
度の上下に対して安定であった。また、Ｘ線回折によ
り、正極に変化は見られず、負極にはLi2PtO3のピーク
が表れたのでリチウムイオンが導電種であると確認され
た。First, when the stability was repeatedly evaluated by raising and lowering the temperature from 20 ° C. to 800 ° C., almost no deterioration was observed, and the stability was high and low. Also, no change was observed in the positive electrode by X-ray diffraction, and a peak of Li 2 PtO 3 appeared in the negative electrode, so it was confirmed that lithium ions were the conductive species.
測定周波数範囲は102kHzから106kHz、測定温度範囲は
20〜600℃とした。この焼結体の導電率を示すグラフを
第２図に示した。第２図から、導電率は熱活性化型の温
度依存性を示し、温度が高い程導電率が大きい。また、
測定周波数については周波数依存性を示しているが、温
度が高い程周波数依存性は小さく、このことは、イオン
と電子の混合電子体であることを示している。The measurement frequency range is 10 2 kHz to 10 6 kHz, and the measurement temperature range is
20-600 ° C. FIG. 2 is a graph showing the conductivity of the sintered body. From FIG. 2, the conductivity shows the temperature dependence of the thermal activation type, and the higher the temperature, the larger the conductivity. Also,
Although the measurement frequency shows frequency dependence, the higher the temperature is, the smaller the frequency dependence is, which indicates that it is a mixed electron body of ions and electrons.
輸率に計算についての上記（１）式に基づき、イオン
の輸率は0.998と計算され、イオン電導が大きく支配し
ていると結論することができる。Based on the above equation (1) for calculating the transport number, the ion transport number is calculated to be 0.998, and it can be concluded that ion conduction is dominant.
上記焼成体の強度を、曲げ試験機（インストロン社
製、1185）を用いて、4.2mm×3.2mm×24.7mmの大きさの
測定試料について、支点間距離16mm、クロスヘッド速度
0.5mm/minで３点曲げ試験により測定したとろ13.2kg/mm
2（129.4MPa）であった。The strength of the fired body was measured using a bending tester (1185, manufactured by Instron Co., Ltd.) for a measurement sample having a size of 4.2 mm × 3.2 mm × 24.7 mm, a distance between supporting points of 16 mm, and a crosshead speed.
13.2 kg / mm, measured by a three-point bending test at 0.5 mm / min
2 (129.4MPa).
［比較例１］ 焼結体中のLi2O:Al2O3:TiO2のモル比が2:1:6となるよ
うに原料を配合した他は実施例１と同様にして焼結体を
作製した。この焼結体の結晶構造をＸ線回折で調べたと
ころ、第３図のような回折図となり、△で示すLi2Al2Ti
4O12（Li2O・Al2O3・4TiO2）のピークと、×で示すLi2T
i3O7（Li2O・3TiO2）のピークにより、これら２相から
なっていることが確認された。導電率は実施例１の場合
とほぼ同様な傾向を示し、イオンの輸率は0.998と計算
された。しかし、この焼結体は実施例１と同様にして強
度を測定したところ、0.66kg/mm2（6.47MPa）と非常に
低く、各種の用途に用いることができないものであっ
た。Comparative Example 1 A sintered body was prepared in the same manner as in Example 1, except that the raw materials were mixed such that the molar ratio of Li 2 O: Al 2 O 3 : TiO 2 in the sintered body was 2: 1: 6. Was prepared. The crystal structure of the sintered body where was examined by X-ray diffraction, it becomes diffraction diagram as shown in FIG. 3, Li 2 Al 2 Ti indicated by △
4 O 12 (Li 2 O ・ Al 2 O 3・ 4TiO 2 ) peak and Li 2 T indicated by ×
The peak of i 3 O 7 (Li 2 O.3TiO 2 ) confirmed that these two phases were formed. The conductivity showed almost the same tendency as in Example 1, and the ion transport number was calculated to be 0.998. However, when the strength of this sintered body was measured in the same manner as in Example 1, it was extremely low at 0.66 kg / mm 2 (6.47 MPa) and could not be used for various purposes.
［比較例２］ 焼結体中のLi2O:Al2O3:TiO2のモル比が1:1:4となるよ
うに原料を配合した他は、実施例１と同様にして焼結体
を作製した。この焼結体の結晶構造はＸ線回折の結果、
Li2O・Al2O3・4TiO2のピークを示した。導電率を実施例
１と同様な傾向で、実施例１よりもやや高い値を示し
た。しかし、この焼結体は実施例１と同様にして強度を
測定したところ、1.62kg/mm2（15.9MPa）と非常に低
く、実際の使用には耐えないものであった。Comparative Example 2 Sintering was performed in the same manner as in Example 1 except that the raw materials were mixed such that the molar ratio of Li 2 O: Al 2 O 3 : TiO 2 in the sintered body was 1: 1: 4. The body was made. As a result of X-ray diffraction,
It showed a peak of Li 2 O · Al 2 O 3 · 4TiO 2. The conductivity was similar to that of Example 1 and was slightly higher than that of Example 1. However, when the strength of this sintered body was measured in the same manner as in Example 1, it was very low at 1.62 kg / mm 2 (15.9 MPa), and was not endurable for actual use.
［発明の効果］ 本発明にかかるリチウムイオン電導性複合焼結体は、
優れたリチウムイオン導電性に加えて、高い強度を有す
るので、信頼性のある材料として、固体電解質等に用い
ることができる。さらに緻密に焼結されたセラミックス
であるため、高温でのリチウムの同位体分離や高温セン
サー等の分野において用いるのに好適である。[Effects of the Invention] The lithium ion conductive composite sintered body according to the present invention is
Since it has high strength in addition to excellent lithium ion conductivity, it can be used as a reliable material for solid electrolytes and the like. Further, since the ceramics are densely sintered, they are suitable for use in fields such as isotope separation of lithium at a high temperature and high temperature sensors.
第１図は、実施例１の焼結体のＸ線回折図であり、第２
図は、その焼結体の導電率を示すグラフである。 第３図は、比較例１の焼結体のＸ線回折図である。FIG. 1 is an X-ray diffraction diagram of the sintered body of Example 1, and FIG.
The figure is a graph showing the conductivity of the sintered body. FIG. 3 is an X-ray diffraction diagram of the sintered body of Comparative Example 1.
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.6，ＤＢ名) C04B 35/42 - 35/49 H01M 10/36 - 10/40 H01M 6/18 H01B 1/06 ＣＡ（ＳＴＮ) ＲＥＧＩＳＴＲＹ（ＳＴＮ)──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. 6 , DB name) C04B 35/42-35/49 H01M 10/36-10/40 H01M 6/18 H01B 1/06 CA (STN ) REGISTRY (STN)
Claims (1)
相の結晶相を含むことを特徴とするリチウムイオン導電
性複合焼結体。1. A Li 2 O · Al 2 O 3 · 4TiO 2 and 2 of rutile (TiO 2)
A lithium-ion conductive composite sintered body comprising a crystalline phase.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2110887A JP2944142B2 (en) | 1990-04-26 | 1990-04-26 | Lithium ion conductive composite sintered body |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2110887A JP2944142B2 (en) | 1990-04-26 | 1990-04-26 | Lithium ion conductive composite sintered body |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0412057A JPH0412057A (en) | 1992-01-16 |
| JP2944142B2 true JP2944142B2 (en) | 1999-08-30 |
Family
ID=14547212
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2110887A Expired - Fee Related JP2944142B2 (en) | 1990-04-26 | 1990-04-26 | Lithium ion conductive composite sintered body |
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| Country | Link |
|---|---|
| JP (1) | JP2944142B2 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002196858A (en) | 2000-12-25 | 2002-07-12 | Sony Corp | Electronic equipment |
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1990
- 1990-04-26 JP JP2110887A patent/JP2944142B2/en not_active Expired - Fee Related
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| Publication number | Publication date |
|---|---|
| JPH0412057A (en) | 1992-01-16 |
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