Gel Electrolytes For Dye Sensitized Solar Cells
Replacing liquid electrolytes with solid or quasi-solid electrolytes facilitates the production of photovoltaic cells using continuous manufacturing processes, such as roll-to-roll or web processes, thus creating inexpensive, lightweight photovoltaic cells using flexible plastic substrates.
1 . An electrolyte composition adapted for use in a solar cell, the electrolyte composition comprising, in solution:
a gelling compound comprising a metal ion or a compound of the formula MiXj; and
an ionic liquid comprising an imidazolium iodide.
2 . The electrolyte composition of claim 1 , further comprising an organic compound capable of complexing with the metal ion at a plurality of sites
3 . The electrolyte composition of claim 1 , wherein the metal ion comprises a lithium ion.
4 . The electrolyte composition of claim 2 , wherein the organic compound is selected from the group consisting of poly(4-vinyl pyridine), poly(2-vinyl pyridine), polyethylene oxide, polyurethanes, and polyamides.
5 . The electrolyte composition of claim 1 , wherein the gelling compound is a lithium salt.
6 . The electrolyte composition of claim 5 , wherein the lithium salt has the formula LiX, wherein X is an iodide, bromide, chloride, perchlorate, thiocyanate, trifluoromethyl sulfonate, or hexafluorophosphate.
7 . The electrolyte composition of claim 3 , further comprising iodine at a concentration of at least about 0.05 M.
8 . The electrolyte solution of claim 1 wherein i and j are ≧1, X is an anion, and M is selected from the group consisting of Li, Cu, Ba, Zn, Ni, lanthanides, Co, Ca, Al, and Mg.
9 . The electrolyte solution of claim 8 , wherein the anion is selected from the group consisting of chloride, perchlorate, thiocyanate, trifluoromethyl sulfonate, and hexafluorophosphate.
10 . A method of gelling an electrolyte solution for use in a dye-sensitized solar cell, the method comprising the steps of:
providing an electrolyte solution;
adding to the electrolyte solution a material capable of complexing at a plurality of sites; and
adding to the electrolyte solution a metal ion that complexes at the sites thereby forming a gel.
11 . The method of claim 10 , wherein the steps are performed at a temperature below 50° C.
12 . The method of claim 10 , wherein the steps are performed at standard pressure.
13 . The method of claim 10 , wherein the electrolyte solution has a gelling rate controlled by changing a concentration of counter ions in the electrolyte solution.
14 . The method of claim 10 , wherein the metal ion is a lithium ion.
15 . An electrolyte composition adapted for use in a solar cell, the electrolyte comprising:
at least about 90 wt % of an ionic liquid comprising an imidazolium iodide;
an amount of water ranging from 0 to 10 wt %;
iodine at a concentration of at least 0.05 M; and
methyl-benzimidazole.
16 . The electrolyte composition of claim 15 , wherein the ionic liquid is selected from the group consisting of butylmethylimidazolium iodide, propylmethylimidazolium iodide, hexylmethylimidazolium iodide and combinations thereof.
17 . The electrolyte composition of claim 15 , further comprising LiCl.
18 . The electrolyte composition of claim 17 , wherein the amount of LiCl is between about 1 wt % LiCl and 6 wt % LiCl.
19 . The electrolyte composition of claim 17 , wherein the amount of LiCl is at least about 1 wt % LiCl.
20 . The electrolyte composition of claim 17 , wherein the amount of LiCl is less than about 6 wt % LiCl.
21 . The electrolyte composition of claim 15 , further comprising LiI.
22 . The electrolyte composition of claim 21 , wherein the amount of LiI is between about 1 wt % LiI and 6 wt % LiI.
23 . The electrolyte composition of claim 21 , wherein the amount of Li is at least about 1 wt % LiI.
24 . The electrolyte composition of claim 21 , wherein the amount of LiI is less than about 6 wt % LiI.