Optically transparent polymer electrolyte films
Provided are electrolyte films or cells for use in variety of applications, such as electrochromic windows. An electrolytic film comprises a polymer layer, such as thermoplastic polyurethane or polymethyl methacrylate, and an electrolyte within the polymer layer. The electrolyte comprises a salt and a plasticizer. The plasticizer comprises one or more materials that are selected to provide sufficient conductivity and optical transparency for operation of the electrolyte film in an application requiring substantial optical clarity and switching speed, such as a smart window.
1. An electrolyte film comprising:
a polymer layer;
an electrolyte within the polymer layer, wherein the electrolyte comprises a salt and a plasticizer; and
wherein an Ra between the plasticizer and the polymer layer is less than about 5.0.
2. The film of claim 1 , wherein the film comprises a haze of about 2% or less as measured by ASTM D1003-13.
3. The film of claim 1 , wherein the film has an ionic conductivity of at least about 3.85×10 5 Siemens/cm.
4. The film of claim 1 , wherein the electrolyte is substantially liquid.
5. The film of claim 1 , wherein the electrolyte is a gel.
6. The film of claim 1 , wherein the plasticizer comprises an organic carbonate and a second material selected from the group consisting of dibenzoate, an acrylate monomer, a phthalate, an aliphatic ester, a non-aliphatic ester, an ethylene glycol bis, a trimellitate, a sebacate, an adipate, a terephthalate, a gluterate, a glyceride, an azelate, a maleate, an epoxidized soybean oil, glycols and polyethers, organophosphates, alkyl citrates, glycerol and acetylated monoglycerides or a mixture thereof.
7. The film of claim 6 , wherein the second material has a volume percentage of about 20% to about 80% of the plasticizer.
8. The film of claim 1 wherein the salt is a lithium salt.
9. The film of claim 6 , wherein the organic carbonate is selected from the group consisting of diethyl carbonate, propylene carbonate, ethylene carbonate, gammabutryrolactone, dimethyl carbonate, methyl ethyl carbonate, glycerin carbonate, butylene carbonate, alkylene carbonate and combinations thereof.
10. The film of claim 9 , wherein the organic carbonate is selected from the group consisting of diethyl carbonate, propylene carbonate and ethylene carbonate.
11. An electrolyte film comprising:
a polymer layer;
an electrolyte within the polymer layer, wherein the electrolyte comprises a salt and a plasticizer; and
wherein the plasticizer comprises a mixture of a combination of at least two of propylene carbonate, diethyl carbonate and ethylene carbonate, and a material selected from the group consisting of a dibenzoate, an acrylate monomer, a phthalate, an aliphatic ester, a non-aliphatic ester, an ethylene glycol bis, a trimellitate, a sebacate, an adipate, a terephthalate, a gluterate, a glyceride, an azelate, a maleate, an epoxidized soybean oil, glycols and polyethers, organophosphates, alkyl citrates, glycerol and acetylated monoglycerides or a mixture thereof.
12. The film of claim 11 , wherein the plasticizer comprises propylene carbonate and ethylene carbonate.
13. The film of claim 11 , wherein the plasticizer comprises propylene carbonate and diethyl carbonate.
14. The film of claim 11 , wherein the plasticizer comprises ethylene carbonate and diethyl carbonate.
15. An electrolyte film comprising:
a polymer layer;
an electrolyte within the polymer layer, wherein the electrolyte comprises a salt and a plasticizer; and
wherein the plasticizer comprises an organic carbonate selected from the group consisting of propylene carbonate, diethyl carbonate, and ethylene carbonate and a material selected from the group consisting of ethylene glycol, an oxygenated solvent, or a mixture thereof.
16. The film of claim 15 , wherein the material comprises ethylene glycol.
17. The film of claim 15 , wherein the material comprises the oxygenated solvent.
18. An electrochromic cell comprising:
first and second layers of an optically transparent material; and
an ion conductive layer between the first and second layers, the ion conductive layer comprising:
a polymer layer;
a salt; and
a plasticizer, wherein an Ra between the plasticizer and the polymer layer is less than about 5.0.
19. The film of claim 18 , wherein the plasticizer comprises an organic carbonate and a second material selected from the group consisting of dibenzoate, an acrylate monomer, a phthalate, an aliphatic ester, a non-aliphatic ester, an ethylene glycol bis, a trimellitate, a sebacate, an adipate, a terephthalate, a gluterate, a glyceride, an azelate, a maleate, an epoxidized soybean oil, glycols and polyethers, organophosphates, alkyl citrates, glycerol and acetylated monoglycerides or a mixture thereof.
20. The film of claim 19 , wherein the organic carbonate is selected from the group consisting of diethyl carbonate, propylene carbonate, ethylene carbonate, gammabutryrolactone, dimethyl carbonate, methyl ethyl carbonate, glycerin carbonate, butylene carbonate, alkylene carbonate and combinations thereof.
21. The film of claim 19 , wherein the organic carbonate is selected from the group consisting of diethyl carbonate, propylene carbonate and ethylene carbonate.