Alkali-metal generator and absorber
Electrodes are positioned substantially in contact with at least one surface of a solid to generate or absorb alkali metals when a voltage is applied between the electrodes.
1. A device for generating an alkali metal in elemental form, the device comprising:
an alkali-containing solid containing the alkali metal in a non-elemental form;
a heater for heating the alkali-containing solid to a temperature of no more than 300° C.;
first and second solid metal electrodes positioned in contact with at least one surface of the alkali-containing solid, at least a portion of the at least one surface of the alkali-containing solid being exposed to a surrounding environment, at least one of the electrodes being an ion-injecting metal electrode; and
electrical interconnects coupled to the first and second solid metal electrodes for interfacing with a driver that applies a voltage between the first and second solid metal electrodes to move ions of the alkali metal through the alkali-containing solid, at least a portion of the ions being converted into elemental form upon reaching one of the solid metal electrodes and thereafter vaporizing in the elemental form from the exposed portion of the at least one surface of the alkali-containing solid into the surrounding environment.
2. The device of claim 1 , wherein the alkali-containing solid is selected from the group consisting of a glass, a glass-ceramic, a multi-phase glass, a compound, a mixture, and a crystalline solid.
3. The device of claim 1 , wherein the metals of the first and second solid metal electrodes are different.
4. The device of claim 1 , wherein the at least one surface comprises:
a top surface of the alkali-containing solid, the first solid metal electrode being in contact therewith; and
a bottom surface of the alkali-containing solid, the second solid metal electrode being in contact therewith.
5. The device of claim 4 , wherein the second solid metal electrode is disposed as a layer on the bottom surface.
6. The device of claim 4 , wherein the first solid metal electrode is disposed in a pattern selected from the group consisting of a finger pattern, an interdigitated pattern, a ring-dot pattern, a mesh pattern, and a star pattern.
7. The device of claim 4 , wherein the first solid metal electrode is disposed as a layer on the top surface.
8. The device of claim 1 , wherein the at least one surface is a single surface, the first and second solid metal electrodes being disposed thereupon in a pattern.
9. The device of claim 8 , wherein the pattern is an interdigitated pattern.
10. The device of claim 8 , wherein the pattern is a ring-dot pattern.
11. The device of claim 1 , further comprising a chamber enclosing the alkali-containing solid and the first and second solid metal electrodes.
12. The device of claim 11 , wherein the chamber is a vacuum chamber.
13. The device of claim 11 , wherein the chamber contains an inert gas.
14. The device of claim 1 , wherein the alkali metal is selected from the group consisting of sodium, potassium, rubidium, cesium, and francium.
15. The device of claim 1 , wherein the ion-injecting metal is selected from the group consisting of silver, copper, and gold.