GPa 級局所応力場を利用した燃料電池電解質評価技術の開発
GPa 級局所応力場を利用した燃料電池電解質
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評価技術の開発
＊
147
＊
大　幸　裕　介
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Development of the screening of fuel cell electrolytes utilizing a GPa-order local stress field
Yusuke DaikoÚ
Ionic conductivities measured under GPa-order high pressure include various information
about ion hopping mechanisms such as the activation volume (ΔV). In this study, we
demonstrate a new method for high-pressure impedance measurements, up to 4 GPa, utilizing
an indentation-induced local stress field. Traditionally, diamond anvil cells have been used for
high-pressure measurements. The current system does not require any pressure mediums or
pressure calibrations. The ΔV for O2− ion conduction in 10 mol% Y2O3-doped zirconia at
500 °C was estimated to be 3.0 cm3 mol−1. ΔV increased with increasing temperatures from
500 to 600 °C. The technique also allows the concurrent determination of the effective elastic
modulus by fitting the experimental data obtained from the indentation load–depth profile
curve with the Hertzian elastic model. The experimental values were consistent with the
theoretical values. Finite element method (FEM) was also applied to evaluate the ΔV.
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>1h]Ç[„ZCÍWm¡€&ÃMÊu
½º ³y€„ZÁ’ŠY$
­%
$[1-3]©{ 1mm ®x£zel… 10Ν ®x¼Òel©
EW 0.1܅ GPa Î$ÙeGErÖ¢&²NA
ÉËÃM$eleRšª¨$(*@rÖ¢(σ)
σ = σo·exp[-(ΔE+PΔV)/RT]
(1)
(σ0ÛV×alPÛeWRۗKo…TÛ¶qœx)¾%P C
o σ œxi[!#›€[)8?,BΔE T Co σ
eWi[!#›€[K¯ ΔV %%˜"%$ΔV (*
@;5:@-Ir$ԓ̸`ƒ”$[4,5]ÖlIrK
C» ΔV ÅO&#XeJrÖ¢D‡$ÒÀ
ŸdKÖÁÆ ΔV ÃM GPa *B4BeW\i˜
"%ÙeoU´(Ć/(2oÕb—eWkK)" c
図１．
GPa 級
1.圧子圧入法を利用した
e l eR š & T ¥
ΔE ÃM– ΔV g_L’s
GPa 高圧インピーダンス測定
µÙe(@:B4@1
eleRšt‚§ GPa µÙe&¦¤$
o
£zelT¥!Q±eW&Í·§i[$
\
¹$[6]}Ž4(=<@6'@9?3?&T¥ ΔV ÃM–ȲNÝÉËÕb—
U~(Ñ[/ÏP)pˆ$jTŸ‹|$
Œ«°Ñ[¡(*@(O2-)
IrK †Ö™ÖÁÆ¥"%$ÐSno[0?.7'(YSZ)&”žÄ†¥eleRš
!#Ùe(@:B4@1!•§o^‰ÃM&‘Â
2015 年 2 月 25 日受理
*
豊田理研スカラー
（名古屋工業大学大学院未来材料創成工学専攻）
148
GPa 級局所応力場を利用した燃料電池電解質評価技術の開発
-1
log(σ / S cm )
Z" / kΩ
10 mol%Y2O3 ±h ZrO2 - 1500 1 û´Ôáā-ùāÄdz½îš½HK2·ø
Ā¦-3?97w~(Inconel625 ä)HK2Ā¦û /KAM8K3- LCR EM7M-½³
JM<4IA06Ò~-½ß÷ 0⇔25 N ûNõ‡{l( 5N Nûß÷
-vNß÷P LCR EM7M-½/KAM8K3-³Hertz ‰ŽF:Iy
êÎw~ •éāÊ')w~_̍g-Îc#ŸýæÒêÎ! COMSOL Multiphysics®5B
;(Ver. 4.4)-½
500* loading '" unloading  w`° vs ß÷ž×
!÷)YSZ €a‰Ž”k-È( Hertz è¡')w
~ •éāÊ-«$(_̍g-êÎu 2a Hertz
F:I fitting Ô¢(ò×: Hertz F:I)-ÈFitting ')
p‰Ž¹! 101 GPa Œ(+ ]! YSZ Inconel w~
‰Ž¹'"D.5K©')Îc](99 GPa)ÞNÝĀ
èñ ӝilͧ¤¶ŽíY½oÜ*-Æï
5 N û(120 s)\“/KAM8K3-³Ô¢-u
2b Èu PÃn!>I1’‘Š*Ù(+*
ß÷'">I1’‘-w~ •éāÊç£l++
100
5N
g'"ƒĀ¹–ÎCJ9;% -u ĄÈSÚ
û!Þ|Á×ü[
Œ(+(1)ˆ') ΔV ! 3.0 cm3/mol ê
50
Î+ ]!™¸](2.1 cm3/mol)ôŸýæÒêÎ')
w~ô^ gd†-hrb‡ fitting -à,'
0
2.1 cm3/mol Í ΔV Œ(+w~ô^ gd†-hr
100
200
300
400
500
*')ăЇ ΔV ­
oÜ*Ù(+*
Z' / kΩ
'wg}V%wgã¨%Qæ8/GFK<.K@I
ａ）
YSZ の 500℃における荷重と
4IăwâØ-½mOâØ ΔV -˜dɇóõLÏZ 図２．
u 2a. YSZ
500*ß
w圧入深さの関係
（赤線は
( ò ×Hertz
íYoÜ*-‚ì#qâØ-½ 500
÷
`° ü[
!
F:I)
モデル）2b) 5 N *
Hertz
100 û#' 25 û§¤¶Ž(‰Ž¹)'"/KAM8
ｂ）5NCJ9;
における cole-cole プロット
K3-íY,YSZ ӝil!ï$(+X½ö cole-cole
(Nö—“ SUS304 -X½) ü[ӝîĂ!Us 500
-3
3
ΔV [cm /mol]
‚œ
U‹!')µšĀ¬kWô²‡'"ÿtªí
o
500
C:
3.0
Y-ÕÖ*
o
550 C: 3.2
-3.5
o
600 C: 3.9
5N
w~w`')w~ÁP¿¼*„Àăwgz-f½
10 N
-4
a› GPa Ñăw/KAM8K3³®¥ë
15 N
20 N
25 N
‰Ž¹&Ň §¤À¶ŽƒĀ¹'"¯ŽlVÊ2
R = 0.9967
qăbºŽíYoÜ*-‚ìw~ô^ 
-4.5
gd†!åþR„À*
ŸýæÒêÎ-f½gd
2
2.5
3
3.5
4
4.5
†-hr Fitting 'xNg ³qÍ ΔV Pressure / GPa
(+Îc+ð¾»lÄː'*ÄËj'e$
500℃における YSZ の圧子直下
Œ(+¢)U‹!›çĀèñ 31HM=K2&ÛTŽ 図３．
u 3. 500* YSZ w
の発生応力と導電率の関係
íY„gz-f½›d¡®…ú
~ÁP
¿¼gƒĀ¹
ü[.
REFERENCES
[1] M. Sakai et al., J. Non-Cryst. Solids, 282, 236-247 (2001). [2] N. Hakiri et al., J. Mater. Res., 24, 1950-1959 (2009).
[3] S. Yoshida et al., J. Mater. Res. 20, 3404-3412 (2005). [4] D. N. Yoon et al., J. Phys. Rev. B, 5, 4935-4945 (1972).
[5] G. A. Samara, Solid State Phys. 38, 1-80 (1984). [6] Y. Daiko et al., Solid State Ionics, 254, 6-10 (2014).