Claims
- 1. A method of preparing a crystalline compound which provides fast sodium ion transport which comprises heating a hydrated orthorhombic crystalline solid having the formula on a water-free basis
- Na.sub.1+x+4y Zr.sub.2-y (SiO.sub.4).sub.x (PO.sub.4).sub.3-x
- where x is between about 1.0 and about 2.8 and y is between 0 and 0.5, at a temperature between about 1,000.degree. C. and about 1,250.degree. C. until the orthorhombic crystalline solid is converted to a homogeneous, fast sodium ion conducting, monoclinic or rhombohedral crystalline sodium zirconium silico-phosphate of the formula indicated above, or a mixture of the two free from any separate, detectable zirconia phase.
- 2. A method of preparing a crystalline compound which provides fast sodium ion transport in accordance with claim 1 in which x is between about 1.8 and about 2.3.
- 3. A method of preparing a crystalline compound which provides fast sodium ion transport in accordance with claim 1 which comprises heating the orthorhombic crystalline solid at a temperature between about 1,100.degree. C. and about 1,225.degree. C.
- 4. A method of preparing a crystalline compound which provides fast sodium ion transport and having the formula:
- Na.sub.1+x+4y Zr.sub.2-y (SiO.sub.4).sub.x (PO.sub.4).sub.3-x
- where x is between about 1.0 and about 2.8 and y is between 0 and 0.5, which comprises the steps:
- heating an aqueous dispersion comprising soda and silica in solution in a mol ratio of soda to silica of between about 0.9:1 and about 4:1 and a powdered zirconium phosphate having the formula Zr(MPO.sub.4).sub.2.zH.sub.2 O where M is hydrogen, sodium or a mixture of hydrogen and sodium, and z is an integer from 0 to 10, in an amount to provide a mol ratio of silica to zirconium phosphate of between about 1.2:1 and about 1.8:1, the proportions of the soda, silica and phosphate in the reaction mixture being in excess of the proportions of these materials in the final product, said heating being conducted at a temperature between about 250.degree. C. and about 350.degree. C., until reaction occurs and a precipitate is formed,
- separating precipitated material from supernatant liquid, and washing and drying such separated precipitate to recover a hydrated orthorhombic crystalline solid, and
- calcining the hydrated orthorhombic crystalline solid at a temperature between about 1000.degree. C. and about 1250.degree. C. until conversion to a homogeneous, fast sodium ion conducting, monoclinic or rhombohedral crystalline, sodium zirconium silico-phosphate of the formula indicated above, or a mixture of the two, free from any separate, detectable zirconia phase, is substantially complete.
- 5. A method of preparing a crystalline compound which provides fast sodium ion transport in accordance with claim 4 in which the mol ratio of soda to silica is between about 1:1 and about 3:1.
- 6. A method of preparing a crystalline compound which provides fast sodium ion transport in accordance with claim 4 in which the aqueous dispersion is heated at a temperature between about 275.degree. C. and about 325.degree. C.
- 7. A method of preparing a crystalline compound which provides fast sodium ion transport in accordance with claim 4 in which the solid product is calcined at a temperature between about 1,100.degree. C. and about 1,225.degree. C.
- 8. A method of preparing a crystalline compound which provides fast sodium ion transport in accordance with claim 4 in which M is hydrogen.
- 9. A method of preparing a crystalline compound in accordance with claim 4 in which x is between about 1.8 and about 2.3.
Parent Case Info
This is a continuation-in-part of U.S. Ser. No. 379,567, filed May 18, 1982, now abandoned.
US Referenced Citations (3)
Foreign Referenced Citations (1)
Number |
Date |
Country |
2052462 |
Jan 1981 |
GBX |
Non-Patent Literature Citations (1)
Entry |
Bayard, M. L., "A Complex Impedance Analysis of the Ionic Conductivity of Na.sub.l+x Zr.sub.2 Si.sub.x P.sub.3-x O.sub.12 Ceramics", J. Electroanal. Chem. 91, (1978), pp. 201-209. |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
379567 |
May 1982 |
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