Ionically conductive asymmetric composite membrane for electrochemical energy system applications

Patent metadata

Field	Value
Publication number	US-11749811-B2
Application number	US-202117388950-A
Country	US
Kind code	B2
Filing date	Jul 29, 2021
Priority date	Mar 25, 2021
Publication date	Sep 5, 2023
Grant date	Sep 5, 2023

Abstract

An ionically conductive asymmetric composite membrane for use in redox flow battery, fuel cell, electrolysis applications and the like is described. It comprises a microporous substrate membrane and an asymmetric hydrophilic ionomeric polymer coating layer on the surface of the microporous substrate layer. The coating layer is made of a hydrophilic ionomeric polymer. The asymmetric hydrophilic ionomeric polymer coating layer comprises a porous layer having a first surface and a second surface, the first surface of the porous layer on the surface of the microporous substrate layer and a nonporous layer on the second surface of the porous support layer. The microporous substrate membrane is made from a different polymer from the hydrophilic ionomeric polymer.

First claim

What is claimed is:

1. An ionically conductive asymmetric composite membrane comprising:
a microporous substrate membrane; and
an asymmetric hydrophilic ionomeric polymer coating layer on a surface of the microporous substrate layer, the coating layer made of a hydrophilic ionomeric polymer, the coating layer comprising;
a porous layer having a first surface and a second surface, the first surface of the porous layer on the surface of the microporous substrate layer; and
a nonporous layer on the second surface of the porous layer;

wherein the microporous substrate membrane is made from a polymer different from the hydrophilic ionomeric polymer.

2. The composite membrane of claim 1 wherein the hydrophilic ionomeric polymer comprises a polysaccharide polymer, a poly(acrylic acid) polymer, a poly(methacrylic acid) polymer, or combinations thereof.

3. The composite membrane of claim 2 wherein the hydrophilic ionomeric polymer comprises the polysaccharide polymer, and wherein the polysaccharide polymer comprises chitosan, alginic acid, hyaluronic acid, dextran, pullulan, carboxymethyl curdlan, κ-carrageenan, μ-carrageenan, τ-carrageenan, carboxymethyl cellulose acid, pectic acid, chitin, chondroitin, xanthan gum, or combinations thereof.

4. The composite membrane of claim 3 wherein the polysaccharide polymer comprises alginic acid, hyaluronic acid, carrageenic acid, or combinations thereof.

5. The composite membrane of claim 1 wherein the microporous substrate membrane comprises polyethylene, polypropylene, polyamide, polyacrylonitrile, polyethersulfone, sulfonated polyethersulfone, polysulfone, sulfonated polysulfone, poly(ether ether ketone), sulfonated poly(ether ether ketone), polyester, cellulose acetate, cellulose triacetate, polybenzimidazole, polyimide, polyvinylidene fluoride, polycarbonate, cellulose, or combinations thereof.

6. The composite membrane of claim 1 wherein the hydrophilic ionomeric polymer is converted from a water-soluble hydrophilic ionomeric polymer.

7. The composite membrane of claim 6 wherein the water-soluble hydrophilic ionomeric polymer is a negatively charged polysaccharide polymer, a positively charged polysaccharide polymer, or combinations thereof.

8. The composite membrane of claim 7 wherein the negatively charged polysaccharide polymer comprises sodium alginate, potassium alginate, calcium alginate, ammonium alginate, sodium hyaluronate, potassium hyaluronate, calcium hyaluronate, ammonium hyaluronate, κ-carrageenan, λ-carrageenan, τ-carrageenan, pectin, carboxymethyl curdlan, sodium carboxymethyl curdlan, potassium carboxymethyl curdlan, calcium carboxymethyl curdlan, ammonium carboxymethyl curdlan, carboxymethyl cellulose, sodium carboxymethyl cellulose, potassium carboxymethyl cellulose, calcium carboxymethyl cellulose, ammonium carboxymethyl cellulose, or combinations thereof.

9. The composite membrane of claim 7 wherein the positively charged polysaccharide polymer is protonated chitosan.

10. A method of preparing an ionically conductive asymmetric composite membrane comprising:
applying a layer of an aqueous solution comprising a water-soluble hydrophilic ionomeric polymer to one surface of a microporous substrate membrane;
drying the coated membrane to form an ionically conductive composite membrane comprising a nonporous water-soluble hydrophilic ionomeric polymer coating layer on the microporous substrate membrane; and
converting the nonporous water-soluble hydrophilic ionomeric polymer coating layer into an asymmetric hydrophilic ionomeric polymer coating layer comprising a porous layer with a nonporous layer on top; wherein the microporous substrate membrane is made from a polymer different from the hydrophilic ionmeric polymer.

11. The method of claim 10 wherein converting the nonporous water-soluble hydrophilic ionomeric polymer coating layer comprises:
simultaneously contacting the nonporous water-soluble hydrophilic ionomeric polymer coating layer with a positive electrolyte solution having a pH of 1.5 or lower and contacting the microporous substrate membrane with a negative electrolyte solution having a pH greater than or equal to the pH of the positive electrolyte solution forming the porous layer with the nonporous layer.

12. The method of claim 11 wherein at least one of: a contacting time is in a range of 10 min to 10 h, and a contacting temperature is in a range of 10° C. to 60° C.

13. The method of claim 10 wherein the aqueous solution comprises an inorganic acid or an organic acid.

14. The method of claim 13 wherein the inorganic acid is HCl, H 2 SO 4 , or H 3 PO 4 .

15. The method of claim 13 wherein the organic acid is acetic acid or lactic acid.

16. The method of claim 10 wherein the water-soluble hydrophilic ionomeric polymer is a negatively charged polysaccharide polymer, a positively charged polysaccharide polymer, or combinations thereof.

17. The method of claim 16 wherein the negatively charged polysaccharide polymer comprises sodium alginate, potassium alginate, calcium alginate, ammonium alginate, sodium hyaluronate, potassium hyaluronate, calcium hyaluronate, ammonium hyaluronate, κ-carrageenan, λ-carrageenan, τ-carrageenan, pectin, carboxymethyl curdlan, sodium carboxymethyl curdlan, potassium carboxymethyl curdlan, calcium carboxymethyl curdlan, ammonium carboxymethyl curdlan, carboxymethyl cellulose, sodium carboxymethyl cellulose, potassium carboxymethyl cellulose, calcium carboxymethyl cellulose, ammonium carboxymethyl cellulose, or combinations thereof.

18. The method of claim 16 wherein the positively charged polysaccharide polymer is protonated chitosan.

19. A redox flow battery system, comprising:
at least one rechargeable cell comprising a positive electrolyte, a negative electrolyte, and an ionically conductive asymmetric composite membrane positioned between the positive electrolyte and the negative electrolyte, the positive electrolyte in contact with a positive electrode, and the negative electrolyte in contact with a negative electrode, wherein the ionically conductive asymmetric composite membrane comprises a microporous substrate membrane with an asymmetric hydrophilic ionomeric polymer coating layer thereon, wherein the coating layer made of a hydrophilic ionomeric polymer, wherein the coating layer comprises a porous layer with a nonporous layer thereon, and wherein the microporous substrate membrane is made from a polymer different from the hydrophilic ionomeric polymer;
the positive electrolyte consisting essentially of FeCl 2 at a concentration of 1.0-4.5 M, NH 4 Cl at a concentration of 1.0-4.0 M or KCl at a concentration of 1.0-3.0 M, HCl at a concentration of 0.05-2.5 M, and glycine at a concentration of 0.01-3.0 M, optionally boric acid at a concentration of 0.01-1.0 M, and optionally FeCl 3 at a concentration of 0.1-1.0 M; and
the negative electrolyte consisting essentially of FeCl 2 at a concentration of 1.0-4.5 M, NH 4 Cl at a concentration of 1.0-4.0 M or KCl at a concentration of 1.0-3.0 M, optionally boric acid at a concentration of 0.01-1.0 M, optionally glycine at a concentration of 0.01-3.0 M, and optionally FeCl 3 at a concentration of 0.1-1.0 M.

20. The redox flow battery system of claim 19 wherein the hydrophilic ionomeric polymer comprises alginic acid, hyaluronic acid, carrageenic acid, chitosan, pectinic acid, pectic acid, carboxymethyl curdlan, carboxymethyl cellulose acid, dextran, pullulan, chitin, chondroitin, xanthan gum, or combinations thereof.

Assignees

• Uop Llc

Inventors

• Liu Chunqing
• Dong Xueliang
• Ba Chaoyi
• Miller Stuart R

Classifications

• H01M8/188

  by recharging of redox couples containing fluids; Redox flow type batteries · CPC title

• H01M8/0239 Primary

  Organic resins; Organic polymers · CPC title

• Y02E60/50

  Fuel cells · CPC title

• H01M8/02 Primary

  Details (electrodes H01M4/86 - H01M4/98) · CPC title

• Y02P20/133

  Renewable energy sources, e.g. sunlight · CPC title