Engineered structure for charge storage and method of making
Engineered structure for charge storage. An electrolyte is disposed between two electrically conducting plates, each plate serving as a base for an aligned array of electrically conducting nanostructures extending from the surface of each plate into the electrolyte. The nanostructures have diameter and spacing comparable to the dimension of an ion of the electrolyte. An electrically insulating separator is disposed between the two plates. A CVD process (or other processes yielding similar results) is used to make the aligned array of electrically conducting nanostructures.
1 ) Engineered structure for charge storage comprising:
an electrolyte disposed between two electrically conducting plates, each plate serving as a base for an aligned array of electrically conducting nanostructures extending from the surface of each plate into the electrolyte, the nanostructures having diameters and spacing comparable to the dimension of an ion of the electrolyte; and an electrically insulating separator between the two plates.
2 ) The engineered structure of claim 1 wherein the nanostructures are nanotubes.
3 ) The engineered structure of claim 2 wherein the nanotubes are single-wall nanotubes.
4 ) The engineered structure of claim 3 wherein the single wall nanotubes have a length in the range of 60 to 500 μm.
5 ) The engineered structure of claim 1 wherein the electrolyte is selected from the group consisting of carbonates, nitrites, sulfoxides, amides, pyrrolidones, esters and ethers.
6 ) The engineered structure of claim 1 wherein the electrolyte is propylene carbonate.
7 ) The engineered structure of claim 1 wherein the electrolyte is an organic electrolyte.
8 ) The engineered structure of claim 1 wherein each plate is a multilayer structure.
9 ) The engineered structure of claim 8 wherein the multilayer structure includes a non-continuous thin film of catalytic material.
10 ) The engineered structure of claim 9 wherein the catalytic material is iron.
11 ) The engineered structure of claim 8 wherein the multilayer structure includes layers of silicon, alumina and iron.
12 ) The engineered structure of claim 1 wherein the spacing between nanostructures is approximately twice the diameter of an electrolyte ion.
13 ) The engineered structure of claim 1 wherein the spacing between the nanostructures is approximately the diameter of an electrolyte ion.
14 ) The engineered structure of claim 1 wherein the separator has a porosity between 40 and 90 percent.
15 ) The engineered structure of claim 14 wherein the separator is a paper based separator or Celgard.
16 ) The process for making an aligned array of electrically conducting nanostructures comprising:
forming a substrate having a surface including a non-continuous thin film of catalytic material; and
growing an aligned array of electrically conducting nanostructures extending from the catalytic material in a chamber whose temperature and pressure are selected to provide desired geometric characteristics for the nanostructure array.
17 ) The process of claim 16 wherein the growing step utilizes chemical vapor deposition.
18 ) The process of claim 16 wherein the non-continuous thin film of catalytic material is made by a pre-growth treatment in a CVD chamber.
19 ) The process of claim 16 wherein chamber temperature is in the range of 500° C. to 850° C.
20 ) The process of claim 16 wherein chamber pressure is in the range of 200 m Torr to 1 atmosphere.
21 ) Engineered structure for charge storage comprising:
an electrode including a nanostructure based film disposed thereon, the film including voids substantially equivalent to the size of a selected electrolyte ion.
22 ) The engineered structure of claim 21 wherein the nanostructure film is a nanotube array.
23 ) The process of claim 18 wherein the pre-growth treatment includes introduction of an inert gas carrier and hydrogen.
24 ) The process of claim 19 wherein the inert gas is argon or helium.