STUDY ON AMMONIUM POLYPHOSPHATE PROTON CONDUCTORS AS ELECTROLYTES FOR NOVEL INTERMEDIATE TEMPERATURE FUEL CELLS
| Project/Area Number |
14550790
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
工業物理化学
|
|---|
| Research Institution | DOSHISHA UNIVERSITY |
|---|
Principal Investigator |
INABA Minoru DOSHISHA UNIVERSITY, FACULTY OF ENGINEERING, ASSOCIATE PEOFESSOR, 工学部, 助教授 (80243046)
|
|---|
| Project Period (FY) |
2002 – 2003
|
| Project Status |
Completed (Fiscal Year 2003)
|
| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2003: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2002: ¥2,500,000 (Direct Cost: ¥2,500,000)
|
|---|
| Keywords | AMMONIUM POLYPHOSPHATE / INTERMEDIATE TEMPERATURE FUEL CELL / PROTON CONDUCTOR / SOLID ELECTROLYTE / THERMAL STABILITY / CATION SUBSTITUTION / MATRIX / プロトン誘電性 / 個体電解質 |
|---|
| Research Abstract |
Ammonium polyphosphates (NH_4PO_3) have high proton conductivity, end are promising materials as electrolytes in intermediate temperature fuel cells operated at around 300℃. In the present study, thermal stability of the ammonium polyphosphates was improved by adding suitable matrix materials and by partial substitution of ammonium ion.
(NH_4)_2SiP_4O_<13> was added as a matrix to form NH_4PO_3/(NH_4)_2SiP_4O<13> composites. The composite (4:1) gave a high proton conductivity of 5.4 mS cm^<-1> at 300℃ with improved thermal stability. The proton conductivity increased with an increase in the content of the matrix. However, NH_4PO_3/(NH_4)_2SiP_4O_<13> composites with molar ratio greater than 8:1 were not stable at 300℃, especially under humidified atmosphere. Hence, the composites with molar ratio lower than 8:1 are preferable in practical use.
(NH_4)_<1-x>K_xPO_3 solid solutions were then prepared to improve thermal stability. (NH_4)_<0.2>K_<0.8>PO_3 kept a solid state even at 400℃ and gave a high proton conductivity. In these solid solutions, NH_3 was eliminated during heating and phase separation into a crystalline phase of KPO_3 and an amorphous phase of HPO_3 occurred. The former phase has a high thermal stability and works as a matrix. The latter phase plays an vital role in proton conduction.
|
Report
(3 results)
Research Products
(3 results)
