Flexible dye-sensitized solar cell using fiber

Abstract

A flexible dye-sensitized solar cell includes: a fiber layer formed of nanofibers; a conductive electrode layer formed on one side of the fiber layer; a photoelectrode layer formed on the conductive electrode layer; a counter electrode layer formed on the other side of the fiber layer; a sealing member for enclosing the fiber layer, the conductive electrode layer, the counter electrode layer and the photoelectrode layer therein so as to seal said layers from the outside; and an electrolyte infiltrated into the fiber layer. A cell body in which an electrode and a photoelectrode are formed on one surface of the fiber that contains an electrolyte therein and a counter electrode is formed on the other side of the fiber is sealed with a polymer film, thus forming a flexible solar cell having an excellent sealing structure for preventing the electrolyte from leaking out of the cell even when pressure is externally applied.

Claims

1. A flexible dye-sensitized solar cell comprising: a fiber layer formed of nanofibers; a conductive electrode layer formed on a first side of the fiber layer; a photoelectrode layer formed on, and in direct contact to, an outer surface of the conductive electrode layer; a counter electrode layer formed on, and in direct contact to, a second side of the fiber layer opposite from the first side of the fiber layer; a sealing member for enclosing the fiber layer, the conductive electrode layer, the counter electrode layer and the photoelectrode layer therein so as to seal said layers from the outside; and an electrolyte infiltrated into the fiber layer, wherein the conductive electrode layer is formed of a metal mesh, and the metal mesh is coated on a surface thereof with titanium, wherein the fiber layer has a titanium dioxide paste applied directly on the first side of the fiber layer, and the titanium coated metal mesh is laminated directly on the titanium dioxide paste applied surface of the fiber layer; wherein the titanium dioxide paste is between the conductive electrode layer and the fiber layer.

2. The flexible dye-sensitized solar cell of claim 1, wherein the fiber layer is formed of nanofibers selected from TiO2, SiO2 and ZrO2 nanofibers.

3. The flexible dye-sensitized solar cell of claim 2, wherein the fiber layer is formed of nanofibers having a diameter of 100 to 900 nm, and has a thickness of 10 to 900 μm.

4. The flexible dye-sensitized solar cell of claim 1, wherein the metal mesh is a stainless steel mesh.

5. The flexible dye-sensitized solar cell of claim 1, wherein the counter electrode layer is formed of platinum.

6. The flexible dye-sensitized solar cell of claim 5, wherein the counter electrode layer is formed to a thickness of 50 to 500 nm.

7. The flexible dye-sensitized solar cell of claim 1, wherein the sealing member is made of polyethylene terephthalate (PET) or polyethylene (PE).

8. The flexible dye-sensitized solar cell of claim 7, wherein the sealing member has a thickness of 10 to 500 μm.

9. The flexible dye-sensitized solar cell of claim 1, wherein the electrolyte is acetonitrile.

10. The flexible dye-sensitized solar cell of claim 9, wherein the electrolyte is infiltrated into the fiber layer by injecting the electrolyte into the fiber layer through a hole formed in the sealing member using an injector.

11. The flexible dye-sensitized solar cell of claim 1, wherein the conductive electrode layer is electrically connected with a first terminal electrode protruding from the sealing member.

12. The flexible dye-sensitized solar cell of claim 11, wherein the counter electrode layer is electrically connected with a second terminal electrode protruding from the sealing member.

13. The flexible dye-sensitized solar cell of claim 12, wherein the second terminal electrode is a titanium wire.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic view of a conventional dye-sensitized solar cell;

(2) FIG. 2 is a schematic view showing the structure of a dye-sensitized solar cell using fiber according to the present invention;

(3) FIG. 3 is a photograph showing the flexibility of the dye-sensitized solar cell according to the present invention;

(4) FIG. 4 is a graph showing the current density of the dye-sensitized solar cell with respect to degree of flexion; and

(5) FIG. 5 is a graph showing the efficiency of the dye-sensitized solar cell with respect to curvature (cm-1).

DETAILED DESCRIPTION OF THE INVENTION

(6) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic view of a conventional dye-sensitized solar cell, FIG. 2 is a schematic view showing the structure of a dye-sensitized solar cell using fiber according to the present invention, FIG. 3 is a photograph showing the flexibility of the dye-sensitized solar cell according to the present invention, FIG. 4 is a graph showing the current density of the dye-sensitized solar cell with respect to degree of flexion, and FIG. 5 is a graph showing the efficiency of the dye-sensitized solar cell with respect to curvature (cm-1).

(7) As shown in FIG. 2, the flexible dye-sensitized solar cell using fiber according to the present invention largely includes a fiber layer 100, a conductive electrode layer 200, a photoelectrode layer 300, a counter electrode 400, a sealing member 500, and an electrolyte 600.

(8) First, a fiber layer 100 is explained.

(9) The fiber layer 100 is formed of nanofibers selected from TiO2, SiO2 and ZrO2. In an embodiment of the present invention, as the fiber layer 100, a glass microfiber filter paper (CHMLAB Group, GF1 grade filter paper) may be used. The thickness of the nanofibers may be about 500 nm, and the fiber layer 100 may be formed to a thickness of about 100 μm. The fiber layer 100 is impregnated with an electrolyte 600, and is enclosed by a sealing member 500 to be isolated from the outside.

(10) A counter electrode layer 400 is formed on the one side of the fiber layer 100. The counter electrode layer 400 is a platinum thin film layer which is formed by applying platinum to one side of a glass paper as the fiber layer 100 to a thickness of 100 nm. In this case, the platinum thin film layer is formed by sputtering or evaporation.

(11) A conductive electrode layer 200 is formed on the other side of the fiber layer 100. The conductive electrode layer 2000 is formed of a stainless steel mesh which is a metal mesh.

(12) In order to form the conductive electrode layer 200, first, a stainless steel mesh, which is a metal mesh, is washed with acetone, ethanol and water, and then dried in an oven at a temperature of 70° C. In this case, the stainless steel mesh is formed of 304 stainless steel (325 meshes).

(13) Thereafter, both sides of the stainless steel mesh are coated with titanium to a thickness of about 300 nm by sputtering. The titanium-coated stainless steel mesh is surface-treated.

(14) Subsequently, a titanium dioxide paste including titanium dioxide (TiO2) particles having a diameter of about 500 nm is primarily applied to a side of the fiber layer 100, the side being opposite to a side provided thereon with the counter electrode layer 400 (platinum thin film layer).

(15) In this state, the surface-treated stainless steel mesh is disposed on the fiber layer 100 primarily coated with the titanium dioxide paste before the titanium dioxide paste is dried, and is then dried in an oven at a temperature of about 70° C. for about 2 hours.

(16) Thereafter, a titanium dioxide paste including titanium dioxide (TiO2) particles having a diameter of about 20 nm is secondarily applied to the upper side of the dried stainless steel mesh disposed on the fiber layer 100.

(17) Finally, the stainless steel mesh secondarily coated with the titanium dioxide paste is heat-treated at a temperature of 480° C. for about 1 hour to attach this stainless steel mesh to the fiber layer 100, thereby forming the conductive electrode layer 200 on one side of the fiber layer 100.

(18) A photoelectrode layer 300 is formed on the lower side of the conductive electrode layer 200. The photoelectrode layer 300 is formed using a titanium dioxide paste.

(19) Specifically, the photoelectrode layer 300 is formed by applying the titanium dioxide paste to the lower side of the conductive electrode layer 200 to a thickness of 20 nm while a mask is disposed over the conductive electrode layer 200. In this case, the photoelectrode layer 300 may be formed by laminating the titanium dioxide paste to a thickness of 20 nm several times.

(20) As described above, the titanium dioxide paste is applied, heat-treated at a temperature of 480° C. for 1 hour, and then immersed into a ruthenium-based N719 dye to form a photoelectrode layer 300 impregnated with the dye.

(21) Next, a sealing member 500 for enclosing the fiber layer 100, the conductive electrode layer 200, the counter electrode layer 400 and the photoelectrode layer 300 therein so as to seal said layers from the outside is formed. The sealing member 500 is made of a transparent polymer film (PET, PE or the like).

(22) In an embodiment of the present invention, the sealing member 500 is formed by applying a PET film having a thickness of about 100 μm using a hot roll coating machine.

(23) Then, a small hole is formed in the sealing member 500, and then a glass paper as the fiber layer 100 is impregnated with acetonitrile as the electrolyte 600 through the hole using an injector.

(24) In this case, a first terminal electrode 710 is formed on the conductive electrode layer 200 by projecting a stainless steel sheet having a predetermined thickness out of the sealing member 500 while electrically connecting this stainless steel sheet with the conductive electrode layer 200, and a second terminal electrode is formed on the counter electrode layer 400 by projecting a titanium wire having a length of about 1 cm and a diameter of 0.1 mm out of the sealing member 500 while electrically connecting this titanium wire with the counter electrode layer 400, thereby completing the flexible dye-sensitized solar cell according to the present invention.

(25) The flexibility of the flexible dye-sensitized solar cell was tested. As a result, it can be ascertained that the flexibility thereof is excellent as shown in FIG. 3.

(26) Further, the current density of the flexible dye-sensitized solar cell with respect to degree of flexion was measured. As a result, it can be ascertained from FIG. 4 that the current density thereof is maintained when the curvature radius thereof is 1.4 cm or more.

(27) Furthermore, from FIG. 5, it can be ascertained that the efficiency thereof is lowered when the curvature radius thereof is less than 1 cm, and that the efficiency thereof is maintained at about 90% when the curvature radius thereof is 1 cm or more. Consequently, it can be ascertained that a flexible dye-sensitized solar cell having a stable efficiency can be obtained when the curvature radium thereof is 1 cm or more.

(28) The present invention relates to a flexible dye-sensitized solar cell using fiber, and, more particularly, to a flexible dye-sensitized solar cell using fiber, which is formed by sealing a cell body, in which an electrode and a photoelectrode are formed on one side of an electrolyte-containing fiber layer and a counter electrode is formed on the other side of the fiber layer, with a polymer film.