Nano-structured lithium-sulfur battery and method of making same
View Patent ↗An apparatus includes a first conductive substrate (e.g., a metal foil) having a first surface; a plurality of conductive stalks (e.g., carbon nano-tubes) extending from the first surface; an electrically insulating coating (e.g., sulfur) about the carbon stalks; a second conductive substrate (e.g., a lithium oxide foil); and an electrolyte (e.g., a polymer electrolyte) disposed between the first surface of the first conductive substrate and the second conductive substrate. In various embodiments: the sulfur is disposed at a thickness of about 3 nanometers+/−1 nanometer; the stalks are at a density such that a gap between them as is between 2 and 200 diameters of an ion transported through the electrolyte; and there is a separator layer within the electrolyte having a porosity amenable to passage by such ions. Also detailed is a method for making the foil with the coated carbon nano-tubes.
1. An apparatus comprising:
a first conductive substrate comprising a first surface;
a plurality of conductive stalks extending from the first surface of the first conductive substrate, the conductive stalks being aligned relative to adjacent conductive stalks;
an electrically insulating coating about the conductive stalks;
a second conductive substrate;
an electrolyte disposed between the first surface of the first conductive substrate and the second conductive substrate; and
a separator layer between the first conductive substrate and the second conductive substrate and on which the electrolyte is disposed along opposed surfaces thereof;
wherein the conductive stalks comprise carbon and the electrically insulating coating comprises sulfur;
wherein the conductive stalks are perpendicular to the first conductive substrate and to the separator layer; and
wherein the plurality of conductive stalks are disposed at a density such that a gap between the stalks having a the electrically insulating coating applied thereabout is between about 2 and 200 diameters of an ion which passes between the second conductive substrate and is attached to the coated stalks by electrical attraction while the apparatus is in operation as a galvanic battery.
2. The apparatus according to claim 1 , in which the conductive stalks extend generally perpendicular from the first surface.
3. The apparatus according to claim 1 , in which the electrically insulating coating comprises sulfur disposed at a thickness of about 3 nanometers.
4. The apparatus according to claim 3 , in which the second conductive substrate comprises an oxide of lithium.
5. The apparatus according to claim 4 , the separator layer having a porosity amenable to passage by ions moving between the first conductive substrate and the second conductive substrate.
6. The apparatus according to claim 5 , in which the electrolyte comprises a polymer.
7. The apparatus according to claim 2 , in which the conductive carbon stalks comprise carbon nano-tubes which are directly attached to the first surface of the first substrate.
8. The apparatus according to claim 1 , in which the apparatus comprises a battery in combination with a bridge circuit which electrically couples a first terminal of the first substrate to a second terminal of the second substrate, and at least one of a load and a voltage potential for discharging or charging the battery disposed within the bridge circuit.
9. The apparatus according to claim 1 , wherein the electrically insulating coating is further disposed on the first surface of the first conductive substrate.