TREA

Electrolyte membrane for electrochemical cell and a method of producing the same

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Information

  • Patent Application
  • 20080075998
  • Publication Number
    20080075998
  • Date Filed
    September 22, 2006
    18 years ago
  • Date Published
    March 27, 2008
    16 years ago
Information
Abstract
[Problem to be Solved]
Description

BRIEF DESCRIPTION OF THE DRAWINGS


FIG. 1 is a cross section for explaining an oxygen concentrator.





DESCRIPTION OF SYMBOLS




  • 1: Air electrode current collector


  • 2: Air electrode plate


  • 3: Electrolyte membrane


  • 4: Air electrode membrane


  • 5: Air electrode current collector


  • 6: Stainless steel container member with oxygen discharge pipe













TABLE 1









PULSED LASER




ABLATION



CONDITIONS












OXYGEN
RE-





PARTIAL
TAINING
ELECTROLYTE MEMBRANE FOR ELECTROCHEMICAL CELLS
MEA-













ELECTRO-
PRES-
TIME
THICK-

ORIENTATION OF PEROVSKITE
SURED


CHEMICAL
SURE
PERIOD
NESS
SEM
CRYSTAL STRUCTURE OF ELECTROLYTE
CURRENT


CELL
(ATM)
(HOUR)
(μm)
OBSERVATION RESULT
MEMBRANE
VALUE (A)

















PRESENT
1
0.05
0.5
1
COLUMNAR CRYSTAL
[112] DIRECTION OF PEROVSKITE
600


INVENTION
2
0.05
1.5
3
STRUCTURE GROWN TO
CRYSTAL STRUCTURE OF SOLID
470



3
0.05
2.0
4
MEMBRANE SURFACE
ELECTROLYTE MEMBRANE HAVING
560



4
0.05
2.5
5
IN THE DIRECTION
COLUMNAR CRYSTAL STRUCTURE
540



5
0.05
3.0
6
PERPENDICULAR TO
GROWN TO MEMBRANE SURFACE IN THE
520



6
0.05
4.0
8
MEMBRANE FACE WAS
DIRECTION PERPENDICULAR TO
505



7
0.05
5.0
10 
FORMED
MEMBRANE FACE WAS ORIENTED
500


COM-
1
0.05
0.2
  0.5*

PERPENDICULARLY TO MEMBRANE FACE
470


PARISON
2
0.05
5.5
11*
POLYCRYSTAL
ISOTROPIC PORTION WAS FORMED
390







WAS FORMED ON
BESIDES PORTION WITH [112]







UPPER FACE OF ALL
DIRECTION ORIENTED







COLUMNAR CRYSTALS
PERPENDICULARLY TO MEMBRANE FACE














3
0.0005*
0.5
  0.1
INSUFFICIENT MEMBRANE FORMING RATE
570



4
0.11*
0.5
1
INSUFFICIENT DENSENESS
—












CONVENTIONAL
—
200 
SINTERED STRUCTURE
—
 40





*DESIGNATES THAT VALUE IS OUT OF CONDITION OF PRESENT INVENTION















TABLE 2









CHARACTERISTIC OF SOLID



ELECTROLYTE FUEL CELL















OUTPUT


SOLID
USED
CELL
OUTPUT
POWER


ELECTROLYTE
ELECTROCHEMICAL
VOLTAGE
POWER
DENSITY


FUEL CELL
CELL IN TABLE 1
(V)
(W)
(W/cm2)
















PRESENT
1
PRESENT
1
0.75
415
3.7


INVENTION
2
INVENTION
2
0.70
400
3.5



3

3
0.70
390
3.4



4

4
0.60
362
3.2



5

5
0.59
350
3.1



6

6
0.58
340
3.0



7

7
0.55
310
2.7


COMPARISON
1
COMPARISON
1
0.50
270
2.4



2

2
0.49
265
2.3



3

3
0.70
400
3.5



4


—
—
—











CONVENTIONAL
CONVENTIONAL
0.3 
200
1.8


















TABLE 3









CHARACTERISTIC OF



OXYGEN CONCENTRATOR

















OXYGEN



ELECTROLYTE MEMBRANE FOR ELECTROCHEMICAL CELLS
LOAD
CELL
RE-
CONCEN-















THICK-

ORIENTATION OF PEROVSKITE
CURRENT
VOLT-
QUIRED
TRATION


OXYGEN
NESS
SEM OBSERVATION
CRYSTAL STRUCTURE OF
DENSITY
AGE
POWER
RATE


CONCENTRATOR
(μm)
RESULT
ELECTROLYTE MEMBRANE
(A/cm2)
(V)
(W)
(cc/min)


















PRESENT
1
1
COLUMNAR
[112] DIRECTION OF PEROVSKITE
1.5
0.43
7.74
50


INVENTION
2
3
CRYSTAL
CRYSTAL STRUCTURE OF SOLID
1.5
0.44
7.92
52



3
4
STRUCTURE GROWN
ELECTROLYTE MEMBRANE HAVING
1.5
0.44
7.92
53



4
5
TO MEMBRANE
COLUMNAR CRYSTAL STRUCTURE
1.5
0.45
8.10
54



5
6
SURFACE IN THE
GROWN TO MEMBRANE SURFACE
1.5
0.45
8.10
54



6
8
DIRECTION
IN THE DIRECTION PERPENDICULAR
1.5
0.46
8.28
54



7
10 
PERPENDICULAR
TO MEMBRANE FACE WAS
1.5
0.46
8.28
54












COM-
1
  0.5*
TO MEMBRANE
ORIENTED PERPENDICULARLY TO
IMPOSSIBLE TO MEASURE DUE TO


PARISON


FACE WAS FORMED
MEMBRANE FACE
SHORT CIRCUIT
















2
11*
POLYCRYSTAL WAS
ISOTROPIC PORTION WAS FORMED
1.5
0.56
10.08 
54





FORMED ON UPPER
BESIDES PORTION WITH [112]





FACE OF ALL
DIRECTION ORIENTED





COLUMNAR
PERPENDICULARLY TO





CRYSTALS
MEMBRANE FACE












3
  0.1
INSUFFICIENT MEMBRANE FORMING RATE
IMPOSSIBLE TO MEASURE DUE TO






SHORT CIRCUIT















4
1
INSUFFICIENT DENSENESS
1.5
0.43
7.74
10














CONVENTIONAL
200 
SINTERED
—
1.5
1.08
19.44 
54




STRUCTURE





*DESIGNATES THAT VALUE IS OUT OF CONDITION OF PRESENT INVENTION





Claims
  • 1. An electrolyte membrane for electrochemical cells that is excellent in oxide ion permeability, and is made of an oxide ion conductor having a component composition expressed by a general formula: La1-XSrXGa1-YMgYO3 (where X=0.05 to 0.3, and Y=0.025 to 0.3), and having a perovskite type crystal structure, wherein the electrolyte membrane has a columnar crystal structure grown to a membrane surface in a direction perpendicular to a membrane face, and the perovskite type crystal structure of the electrolyte membrane having the columnar crystal structure grown to the membrane surface, has a crystal structure with [112] direction oriented perpendicularly to the membrane face.
  • 2. The electrolyte membrane for electrochemical cells excellent in oxide ion permeability, according to claim 1, wherein the electrolyte membrane has a membrane thickness of 1 to 10 μm.
  • 3. An electrochemical cell, wherein a cathode membrane is formed on one of the faces of the electrolyte membrane for electrochemical cells according to one of claim 1 and claim 2, and an anode membrane is formed on the other face.
  • 4. A power generation cell for a solid electrolyte fuel cell, wherein an air electrode membrane is formed on one of the faces of the electrolyte membrane for electrochemical cells excellent in oxide ion permeability, according to one of claim 1 and claim 2, and a fuel electrode membrane is formed on the other face.
  • 5. A solid electrolyte fuel cell incorporating the power generation cell for the solid electrolyte fuel cell according to claim 4.
  • 6. An oxygen pump cell, wherein air electrode membranes are formed on both faces of the electrolyte membrane for electrochemical cells according to one of claim 1 and claim 2.
  • 7. An oxygen concentrator incorporating the oxygen pump cell according to claim 6.
  • 8. A method of producing the electrolyte membrane for electrochemical cells excellent in oxide ion permeability, according to one of claim 1 and claim 2, wherein physical vapor deposition is performed in an oxygen atmosphere by using a target made of a sintered body obtained in a manner that La2O3 powder, SrCO3 powder, Ga2O3 powder, and MgO powder are blended and mixed so as to contain 71 to 81% of La, 66 to 106% of Sr, 66 to 77% of Ga, and 250 to 290% of Mg, with respect to a target composition of an electrolyte membrane for electrochemical cells, expressed by a general formula La1-XSrXGa1-YMgYO3 (where X=0.05 to 0.3, Y=0.025 to 0.3), and are then sintered.
  • 9. The method of producing the electrolyte membrane for electrochemical cells excellent in oxide ion permeability, according to claim 8, wherein the physical vapor deposition is performed in an oxygen atmosphere under an oxygen partial pressure of 0.001 to 0.1 atm.
  • 10. The method of producing the electrolyte membrane for electrochemical cells excellent in oxide ion permeability, according to claim 8, wherein the physical vapor deposition is performed by a pulsed laser ablation method.
  • 11. The method of producing the electrolyte membrane for electrochemical cells excellent in oxide ion permeability, according to claim 9, wherein the physical vapor deposition is performed by a pulsed laser ablation method.