Proton Incorporation, Mixed Alkaline Effect and H+/e^|^minus; Mixed Conduction of Phosphosilicate Glasses and Glass-ceramics

Abstract

Ionic conductivity and proton transport number (t H ) of borosilicate and phosphosilicate glasses were measured at 500°C for intermediate temperature fuel cells. A borosilicate glass (Na 2 O-B 2 O 3 -SiO 2 ) shows t H = 0.04, which increases to 0.2 by doping 3 mol% of P 2 O 5 component. On the other hand, a phosphosilicate glass (Na 2 O-P 2 O 5 -SiO 2 ) shows t H = 0.6 at the same condition. It was found that the Al 2 O 3 doping is indispensable in order to improve both the t H and the chemical durability of the phosphosilicate glasses, and a glass with t H = 1.0 can be obtained for a mixed alkali glass (Na 2 O-K 2 O-P 2 O 5 -SiO 2 ). In the case of non-alkali phosphosilicate glasses (SnO-B 2 O 3 -P 2 O 5 -SiO 2 ), a SnP 2 O 7 phase-dispersed dense glass-ceramic was successfully obtained with Sn/P = 0.52, and the glass ceramic also shows t H = 1.0 at 500°C. By increasing the amount of SnO 2 and decreasing P 2 O 5 components, Sn-rich Sn 2.5 P 3 O 12 phase was precipitated, and the glass-ceramics show a possibility of proton/electron mixed conductivity.

Copper ion beam emission in solid electrolyte Rb4Cu16I6.5Cl13.5

“…Up to date, researchers have explored ion-conducting materials with various mobile ions, e.g., H + , Li + , Na + , K + , Ag + , Cu + , F − , and O 2− . [5][6][7][8][9][10][11][12][13] Among them, Ag + and Cu + ion conducting solid electrolytes attract special attention due to their extremely high ionic conductivity (∼ 10 −1 S/cm) at room temperature, for example, MAg 4 I 5 (with M = NH 4 , Na, Rb) [14] and Na-βalumina. [15] The framework crystalline ion conducting materials are polymorphic systems showing significant differences in ion conductivity between polymorphs.…”