Polyurethane gel electrolytes with improved conductance and/or solvent retention
View Patent ↗Disclosed are gel electrolytes comprising a polymer, which is a cross-linked polyurethane prepared from a poly(alkyleneoxide) triol and a diisocyanate compound; a lithium salt; and a solvent, which is a carbonate solvent, a lactone solvent, or mixtures thereof.
1. A gel electrolyte comprising:
a polymer in about 20 to about 70 wt %;
a lithium salt in about 1 to about 8 wt. %; and
a solvent comprising a carbonate solvent, a lactone solvent, or a mixture thereof;
wherein the polymer is a polyurethane prepared from a poly(alkyleneoxide) triol and a diisocyanate compound, the polymer is sufficiently cross-linked to form a gel in the presence of the solvent, the poly(alkyleneoxide) triol is selected from:
where m, n, and p are selected to form a polymer having molecular weight of about 1,000 to 100,000 g/mol.
2. The gel electrolyte according to claim 1 , wherein the poly(alkyleneoxide) triol comprises glycerin-type poly(alkyleneoxide).
3. The gel electrolyte according to claim 1 , wherein the poly(alkyleneoxide) triol is
where m is selected to form a polymer having molecular weight of about 1,000 to 100,000 g/mol.
4. The gel electrolyte according to claim 1 , wherein the diisocyanate compound is selected from: methylenediphenyl diisocyante (MDI), p-phenylene diisocyante (PPDI), toluene diisocyanate (TDI), o-tolidine diisocyanate (TODD, hexamethylene diisocyanate (HDI), and isophorone diisocyanate (IPDI).
5. The gel electrolyte according to claim 4 , wherein the diisocyanate compound comprises 4,4′-methylenediphenyl diisocyante (MDI).
6. The gel electrolyte according to claim 1 , wherein the polymer is present in about 25-50 wt %.
7. The gel electrolyte according to claim 1 , wherein the polymer is present in about 35 wt %.
8. The gel electrolyte according to claim 1 , wherein the lithium salt comprises lithium perchlorate.
9. The gel electrolyte according to claim 1 , wherein the lithium salt is present in about 3-6 wt %.
10. The gel electrolyte according to claim 1 , wherein the solvent comprises carbonate solvent.
11. The gel electrolyte according to claim 10 , wherein the carbonate solvent comprises dimethyl carbonate, diethyl carbonate, propylene carbonate, ethylene carbonate, vinylene carbonate, or a mixture thereof.
12. The gel electrolyte according to claim 10 , wherein the carbonate solvent comprises propylene carbonate, ethylene carbonate, or a mixture thereof.
13. The gel electrolyte according to claim 1 , wherein the solvent comprises lactone solvent.
14. The gel electrolyte according to claim 13 , wherein the lactone solvent comprises β-propiolactone, γ-butyrolactone, α-methyl-γ-butyrolactone, γ-crotonolactone, δ-valerolactone, γ-valerolactone, γ-caprolactone, ε-caprolactone, or mixtures thereof.
15. The gel electrolyte according to claim 13 , wherein the lactone solvent comprises γ-butyrolactone.
16. The gel electrolyte according to claim 1 , wherein the solvent comprises a mixture of the carbonate solvent and the lactone solvent.
17. The gel electrolyte according to claim 16 , wherein the carbonate solvent comprises propylene carbonate or ethylene carbonate, and the lactone solvent is γ-butyrolactone.
18. A battery comprising:
an anode;
a cathode;
a gel electrolyte between the anode and the cathode where the gel electrolyte includes
a polymer in about 20 to about 70 wt %;
a lithium salt in about 1 to about 8 wt. %; and
a solvent comprising a carbonate solvent, a lactone solvent, or a mixture thereof; wherein the polymer is a polyurethane prepared from a poly(alkyleneoxide) triol and a diisocyanate compound, the polymer is sufficiently cross-linked to form a gel in the presence of the solvent, the poly(alkyleneoxide) triol is selected from:
where m, n, and p are selected to form a polymer having molecular weight of about 1,000 to 100,000 g/mol.