CONDUCTIVE FIBROUS MATERIALS

• US 20110200873A1
• Filed: 10/29/2010
• Published: 08/18/2011
• Est. Priority Date: 10/30/2009
• Status: Active Grant

• Current Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Original Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Inventors: Choi, Jang Wook, Yang, Yuan, Cui, Yi, Hu, Liangbing
• Granted Patent: US 9,138,965 B2
• Time in Patent Office: Days
• US Class Current: 429/188
• CPC Class Codes: B32B 15/16 next to a particulate layer

Abstract

As consistent with various embodiments, an electronic device includes a fibrous material having a conductive coating thereon. The conductive coating includes conductive nanoparticles coupled to fibers in the fibrous material. The structure is implemented in connection with a variety of devices, such as a capacitive device or a battery. Other embodiments are directed to forming conductive fibrous sheets, in dispersing a nanomaterial in a solution and applying the solution to a fibrous sheet, such as commercial paper, to form a conductive sheet.

Claims

1. An electronic device comprising:

a fibrous planar material having a multitude of fibers;

a conductive coating of nanostructures on the surface of the fibers and forming a matrix of conductive-coated fibers; and

conductive materials embedded in the fibrous planar material between the fibers.

2. The device of claim 1, further including electrolyte molecules in the fibrous planar sheet, the molecules having a cross-section that is less than a size of openings, between the coated fibers, that the respective electrolyte molecules occupy.

3. The device of claim 1, wherein the conductive coating is a coating of nanoparticles on the fibers that is between about 5-500 nanometers thick.

4. The device of claim 1, wherein a majority of the conductive-coated fibers are separated from other ones of the conductive-coated fibers by at least about 1 micrometer.

5. The device of claim 1, wherein the conductive coating includes conductive and pseudocapacitor materials respectively coupled to the fibers.

6. The device of claim 1, wherein the fibrous planar material includes at least one of:

cellulose, cotton, textile.

7. The device of claim 1, wherein the fibrous planar material includes at least two of cellulose, cotton and textile.

8. The device of claim 1, wherein at least one of the fibers is a bundle of small fibers.

9. The device of claim 1, wherein at least one of the conductive nanostructures and conductive materials has a shape selected from the group of a sphere, cube, hexagon, triangle, wire, and a tube.

10. The device of claim 1, wherein at least one of the conductive nanostructures and conductive materials is a heterostructure that consists of a combination of two or more materials within a nanostructure.

11. The device of claim 1, wherein the at least one of the conductive nanostructures and conductive materials includes at least one of a semiconductor, a metal and a material having a resistivity in the range of 10⁵ ohm cm to 10⁻

7 ohm cm.

12. The device of claim 1, wherein at least one of the conductive nanostructures and conductive materials includes at least one of an insulating material coated with a conducting shell, and a conducting material coated with an insulating shell.

13. The device of claim 1, further including electrolyte molecules in the fibrous planar sheet, the molecules having a cross-section that is less than the separation between the majority of the coated fibers and including at least one of an aqueous and an organic electrolyte molecule.

14. A battery device comprising:

a current collector including

a fibrous planar material having a multitude of fibers, and

a conductive coating of nanostructures on surfaces of fibers;

a plurality of electrolytes embedded in the coated fibers; and

a plurality of battery electrode particles embedded in the coated fibers.

15. The device of claim 14, wherein at least a portion of the majority of the fibers is spaced at a distance from other fibers that is larger than a cross-sectional distance of the electrolytes and electrode particles.

16. A multilayer battery device comprising:

an anode-side fibrous planar sheet having a plurality of fibers and conductive nanostructures coating the fibers;

an anode layer on the fibrous planar sheet;

an electrolytic separator layer on the anode layer;

a cathode layer on the separator layer; and

a cathode-side fibrous planar sheet having a plurality of fibers and conductive nanoparticles that coat the fibers.

17. The device of claim 16, wherein the conductive nanostructures on the cathode-side fibrous planar sheet consist of a conformal conductive coating on a surface of the cathode-side fibrous planar sheet facing the cathode layer.

18. The device of claim 16, wherein the conductive nanostructures on the anode-side fibrous planar sheet consist of a conformal conductive coating on a surface of the anode-side fibrous planar sheet facing the anode layer.

19. The device of claim 16, wherein

the conductive nanostructures on the cathode-side fibrous planar sheet consist of a conformal conductive coating on a surface of the cathode-side fibrous planar sheet facing the cathode layer, and

the conductive nanostructures on the anode-side fibrous planar sheet consist of a conformal conductive coating on a surface of the anode-side fibrous planar sheet facing the anode layer.

20. The device of claim 16, wherein the anode layer has a conductive electrode that is connected to conductive nanostructures of the anode-side fibrous planar sheet, and separated from other material in the anode layer.

21. The device of claim 16, wherein the cathode layer has a conductive electrode that is connected to conductive nanostructures of the cathode-side fibrous planar sheet, and separated from other material in the cathode layer.

22. The device of claim 16, further including anode and cathode electrodes, respectively connected to the conductive nanostructures of the anode-side and cathode-side fibrous planar sheets, and insulated from anode and cathode materials respectively in the anode and cathode layers.

23. A multilayer capacitive device comprising:

a first conductive sheet layer having a fibrous material coated with a conductive layer;

a second conductive sheet layer having a fibrous material coated with a conductive layer;

a separator layer between the first and second conductive sheet layers; and

wherein the coated conductive layers of each of the first and second sheets respectively contact the separator layer.

24. The device of claim 23, wherein at least one of the coated conductive layers includes pseudocapacitor materials coupled to the fibrous material upon which it is coated.

25. The device of claim 23, wherein the separator layer includes an electrolyte.

26. A battery comprising:

a planer sheet having a plurality of fibers;

conductive nanostructures coupled to the fibers;

a conductive lead at an end of the planar sheet; and

a conductive strip coating on the planar sheet and extending across the sheet to collect current from the conductive nanostructures and conduct the collected current to the conductive lead.

27. The battery of claim 26, wherein

the planar sheet has opposing surfaces and extends to a length and width in a plane, the length and width being an order of magnitude greater than the thickness of the sheet between the opposing surfaces;

and

the conductive nanostructures are formed in a conformal conductive coating on the planar sheet.

28. The battery of claim 26, wherein the conductive nanostructures are coupled to the fibers to form an intertwined matrix of conductive-coated fibers.

29. The battery of claim 26, wherein the conductive strip coating is a paint having a conductive material dispersed therein.

30. The battery of claim 26, wherein the conductive strip coating is arranged in a grid having at least two strips separated by at least about 100 micrometers.

31. A method of making a conductive sheet, the method comprising:

dispersing conductive materials in solution;

applying the solution to a fibrous planar material having a multitude of fibers and forming a conductive layer on the fibers with conductive materials from the solution to form a matrix of conductive-coated fibers; and

embedding conductive materials in the fibrous planer material, between the conductive-coated fibers.

32. The method of claim 31, further including coating pseudocapacitor material on a surface of the fibrous planar material.

33. The method of claim 31, further including coating battery electrode material on a surface of the fibrous planar material.

34. The method of claim 31, wherein forming a conductive layer on the fibers includes setting at least one of the composition, arrangement and thickness of the coating to set the resistance of the conductive sheet.

35. A method of making a conductive sheet, the method comprising:

dispersing conductive materials in solution;

applying the solution to a surface of a fibrous planar sheet to form a conductive coating conformed to the surface of the fibrous planar sheet.

36. The method of claim 35, wherein

dispersing conductive material in solution includes dispersing conductive nanomaterials to form an ink solution, and

applying the solution to a surface of a fibrous planar sheet includes applying the ink solution to the fibrous planar sheet.

37. The method of claim 35, wherein

dispersing conductive material in a solution includes dispersing conductive nanomaterials to form an ink solution, and

applying the solution to a surface of a fibrous planar sheet includes applying the ink solution in a pattern on the fibrous planar sheet to form a patterned conductor on the fibrous planar sheet.

38. A method of making a multilayer battery, the method comprising:

dispersing conductive materials in solution;

applying the solution to fibrous sheets to couple the conductive materials to fibers on a surface of the sheets and form conductive coatings thereon;

providing an anode layer on the coated surface of a first one of the coated sheets to electrically couple the anode layer to the coated surface of the first one of the coated sheets;

providing an electrolyte separator layer on the anode layer;

providing a cathode layer on the electrolyte separator layer; and

providing a second one of the coated sheets on the cathode layer to electrically couple the anode layer to the coated surface of the second one of the coated sheets.

39. The method of claim 38, wherein providing an anode layer and providing a cathode layer respectively include

providing an anode electrode and a cathode electrode respectively coupled to the coated surfaces of the first and second coated sheets, and

providing an anode material and a cathode material that are respectively electrically insulated from the anode electrode and the cathode electrode and coupled to the coated surfaces of the first and second coated sheets.