SU1095567A1 - Solid electrolyte - Google Patents

Abstract

SOLID ELECTROLYTE containing stabilized zirconia and bismuth-containing additive. sp mi: m (; -kltt: -,: o o ,,, -,,,;; not comprehending that, in order to increase the electrothermal conductivity and decrease the sintering temperature, it contains as an additive a solid solution containing 18-22 mol.% rare earth oxide and 78-82 molo% bismuth oxide, in the following ratio of components, mol.%: Stabilized zirconia 80-98 Solid solution containing 1822 mol.% rare earth oxide and 7882 mA. oxide (L bismuth 2-20 C

Description

The invention relates to the refractory industry and can be used for the manufacture of solid electrolytes by electrochemical systems (oxygen activity sensors for gas and liquid metal media, high-temperature fuel cells, oxygen pumps, etc.). .

Known solid electrolyte based on stabilized zirconia.

Its disadvantages are low electrical conductivity (not exceeding for a better solid electrolyte 0.91 ZrOa + 0.09 0.01 and 0.1. At 600 and respectively), as well as a high sintering temperature - higher than 1600 ° C. -.

A known refractory mass for the manufacture of vacuum-tight articles,

o in particular of solid electrolytes containing, in wt.%: bismuth oxide

SP 0.1 - 3.0, titanium dioxide 0.05-0.5.

Ate and stabilized zirconium dioxide or the rest.

The disadvantages of this material are also low electrical conductivity (0.003 0.03 Ohm cm at 600 and respectively) and high sintering temperature tag.

The closest in technical essence and the achieved positive effect to this technical solution is a solid electrolyte containing stabilized zirconium dioxide and an additive of extruded oxide in the following ratio of components: com., Mass.%:,,; -. ; ,; . ., Stzb1 schuiruiddny dioxide t) (C horses OcHOBia Oxide bismuth0, However, this solid electrolyte has a low electrical conductivity (Oy012 OyH. And. It at 600 and respectively) and in the low sintering temperature (1550.), ;; -.;.: - / - -: l; - ::.:; u :: - -: - The low electrical content of the Hof-o solid electrolyte is a high heat source, and you can’t use it at temperatures below that imposes restrictions on the use of electrodes and materials like above The sintering electrode of the sintering stage leads to the firing of solid electrolyte from the substrate and requires the use of high-temperature furnaces, and also evaporates the bismuth oxide especially at higher temperatures, which negatively affects the performance of solid electrolytes. In addition, pure Bismuth oxide, a material with mixed conduction, makes a significant contribution to reducing the proportion of oxygen-ionic persistence of solid electrolyte. The evaporation of bismuth oxide above its melting point () impairs sintering of the solid electrolyte, and therefore the sintering action of bismuth oxide decreases. The aim of the proposed technical solution is to increase the electrical conductivity of the solid electrolyte and reduce the sintering temperature. The goal is achieved by the fact that a solid electrolyte, including stabilized zirconia and a bismuth-containing additive, as the latter contains a solid solution containing 18-22 mol.% Ox. and rare earth element and 7882 mol.% bismuth oxide with the following ratio of components, mol.% Stabilized zirconia 80-98 Solid solution containing 1822 mol.% oxide of rare earth element 7882 mol.% bismuth oxide2–20 The proposal solves the problem of increasing the performance characteristics of a solid electrolyte by increasing its conductivity, and also simplifies the process of obtaining a solid electrolyte by reducing the sintering temperature. The essence of the proposal is that, being an oxygen-ion conductor with electrical conductivity that is 20-100 times higher than the electrical conductivity of stabilized zirconia, a solid solution of 18-22 mol% of rare-earth oxide in bismuth oxide creates a continuous film around the grains of silica and sharply increasing the electrical conductivity of the material, and the effect is observed when at least 2 moles, Z are present in the solid electrolyte. More than a visok compared to pure bismuth oxide, the refractoriness of the emitted solid solution (l.) Allows, firstly, to increase the total content of the additive to 20 mol%, while maintaining sufficient mechanical strength at a temperature of 600-900 C (operating temperature of solid electrolytes), In the process, to form a liquid phase during the period of maximum sintering rate of hsrconium dioxide (1100-1300 C), which significantly accelerates the sintering of solid electrolyte and increases the density. More than 20 mol.%, The addition of solid electrolyte 18-22 mol.% Of rare earth oxide in bismuth oxide to stabilized zirconia is irrational, since the conductivity increases slightly, but the maximum application temperature decreases sharply due to a decrease in mechanical strength at elevated temperatures. The choice of a solid solution of 18–22 Iol.% Rare-earth oxide in bismuth oxide as an additive is due to the achievement of the maximum electrical conductivity of the solid electrolyte and the minimum sintering temperature. Use as an additive of a solid solution containing less than 18 mso1,% oxide of a rare-earth element, leads to a decrease in the electrical conductivity of the solid electrolyte, as can be seen from the table (examples 7 and 21). With a solid solution containing more than 22 rare earth oxide in bismuth oxide, the electrical conductivity does not change much, but the sintering temperature increases (examples 11 and 25). In addition, increasing the content of the oxide of a rare-earth element in a solid solution is not rational, since it increases the cost of a solid electrolyte. As an additive to stabilized zirconia, for example, one can use crucible solutions of yttrium, europium, lutetium, and other rare earth elements in bismuth oxide. P ROME er. Solid electrolytes are prepared in the desired manner. Pre-synthesized using. The method of co-precipitating components from aqueous solutions of stabilized zirconia and the addition of solid solutions of rare earth oxides in bismuth oxide are mixed in the proportions indicated in table. (As additives, solid solutions of yttrium oxide in bismuth oxide and solid solutions of europium oxide in oxide are used. bismuth). The resulting mixtures are ground in an agate mortar, balances of 5x5x30 mm in size are pressed from the masses, which are calcined in a silicon silicate furnace in the temperature range of 1150-1650 ° C (for preparing samples with zero open porosity). The ends of the samples are platinized and the electrical conductivity of the two | contact4 method is determined at a frequency of 3 kHz in the temperature range of 500-1100 G. Composition and properties | The samples examined are listed in the table. I From the table it can be seen that the introduction of a 18–22 small solution in stabilized dioxide – zirconium to a small.% Oxide of a rare-earth element in bismuth hydroxy in an amount of 2–20 mol.% Significantly increases the conductivity and decreases the sintering temperature of the solid electrolyte. Increasing the electrical conductivity of a solid electrolyte improves the performance properties of electrochemical systems and reduces the temperature of their work. Reducing the sintering of the tetratorate, solid electrolytic zrolit will ensure a reduction in the marriage during firing and reduce the cost of their manufacture.

zirconium dioxide 99

Bismuth oxide1

Stabilized Zirconia 99

Bismuth oxide solid solution1

0.8 V10z + 0.2 s

Stabilized dioxide, zirconium 98

1580

Oh, of 2

0.11 Prototype

0.012

0.11

1550

Solid solution of yttrium oxide in bismuth oxide2

0.82 BiOj + 0.18 Yj, O

.

Stabilized DIOXIDE, zirconium; 98

A solid solution of yttria oxide bismuth oxide 2

0.8, + 0.2

11Irconi 9o Stabilized Dioxide

Yttrium oxide solid solution in bismuth oxide 2

0.78 BJ.2.03 0.22

.

Stabilized Dioxide 1CHRKONII90

Yttrium oxide solid solution in bismuth oxide 10

0.83 0.17,

.

Stabilized Zirconia 90

Solid solution

yttria oxide

in bismuth oxide Yu

0.82 V1.0e + 0.18 YgO,

.

Zirconium Stabilized Oxide 90

Solid solution

yttria oxide

in bismuth oxide10

0.8 0.2 YjjO,

0

Stabilized Zirconia 90

Yttria oxide solid solution

10 bismuth oxide

eight /

1095567 Continuation of the table

1430

(), 115

0,0126

1430

0.013

0.12

1430

0.013

0.12

1180

0,0120

0,117

1200

0.0147

0.139

0.015

0.142

1200

0.015

1200

0.139 0.78 0.22, Stabilized Zirconia dioxide. 90 A solid solution of yttrium oxide in bismuth oxide 10102 0.77 0.23 Yj, 03 Stabilized zirconia 80 A solid solution of yttria oxide in bismuth 20 20202 0.82 Bi2, 0.18 T (0) Stable & schizirovanny zirconia 80 Solid solution yttrium oxide in bismuth oxide 20, 1120 0.8 V 1263 + 0.2 Stabilized daoxd zirconium 80 A solid solution of yttrium oxide in bismuth oxide 201120 0.78 0, Stabilized zirconia 98 A solid solution of oxide erot 1 bismuth oxide 211450 0.82 Idr, 0 , 18 StaC lysed dioxide CIRCO1SHYA98 Solid solution of europium oxide in bismuth oxide 21050, 8, 2 EUgOg

Continuation of table j, 01030,128. , 015 0.147 0160.130, 01560.147, 012b0.115, 0130.12

Stabilized

. zirconium dioxide 98

 solution of europium oxide in oxvde bismuth2

0.78 0.22 EUjO

Hundred iairovanny

Zirconia 90

Solid solution

oxide

in bismuth oxide10

 ,18

Stabilized Zirconia 90

Solid solution

europium oxide

in bismuth

0,8), 2 ECD

 Stabilized.

Zirconia 9O

 solution

europium oxide in

1 zmutu oxide 10

0.78 V1.0d + 0.22

Zirconium Stabilized Dioxide Ø 80

Solid solution

europium oxide in

shsmut oxide20

0.83 V12rz 0.17

Stabilized

zirconia 80

Solid solution

europium oxide 8

oxmw bismuth20

0.82 Bi Dj-fO, 18.

Stabilized Zirconia 80

. Solid solution

Table continuation.

      - -

0.013

0.115

1450

0.17

0,0175

1210

0/18

1210

", 018

0, olb

SHO

0.175

1120

OrOl55

0.0208

1140

0.256

13

europium oxide in

bismuth oxide 20

0.8 Big Oj + OjZ

four,

Stabilized Zirconia 80

Solid solution

europium oxide in

bismuth oxide 20

0.78, 22

five,

Stabilized Zirconia 80

Solid solution

europium oxide in

bismuth oxide20

0.77, .3 EU2.C3

6

Stabilized Zirconia 90

Yttrium oxide solid solution in bismuth oxide 10

0.82 Bi (+ 0.18

7

Stabilized dioxide SCH1RKONII90

Yttrium oxide solid solution in bismuth oxide 10

0.8 Bi Oj-fO, 2 Yj, 03

eight.

Stabilized Zirconia 90

Yttrium oxide solid solution in bismuth oxide 10

 Bi., 22

Stabilized

9. Darkonium dioxide 90

Solid solution

europium oxide in

bismuth oxide10

0.82, 18 EujO3

14

109556 / Continuation of the table)

1140

0.27

0.021

0.256

0.021

1140

0.232

1160

0.0147

0.123

1170

1170

0.13

0; 015

1170

0.123

1180

0.15

0,0161

Stabilized Zirconia 90

Tvfdy solution

europium oxide in

bismuth oxide 10

0.8 Bij03 + 0.2 EugOj

Stabilized dooxnd zirconia 90

Solid solution

europium oxide

in bismuth oxide 10

0.78 Bij03 + 0.22 Note.

Table continuation

1180

0.017 0.16

0,017

1180

0.15 In Examples 1-25, Shfkoni dioxide was used, Stabilized with 9 mop.% Of scadi oxide. In examples 26-31, zirconium dioxide Stabilized with 9 mol X of yttrium oxide was used.

Claims (2)

SOLID ELECTROLYTE, containing stabilized zirconia and a bismuth-containing additive, 2 characterized in that, in order to increase electrical conductivity and reduce sintering temperature, it contains as an additive a solid solution containing 18-22 mop.% Rare earth oxide and 78-82 mol.% Bismuth oxide, in the following ratio of components, mol. X: Stabilized Zirconia 80-98 Solid solution containing 1822 mol. Ред rare earth oxide and 7882 mol.% Bismuth oxide 2-20