Redox-Flow Batteries Employing Oligomeric Organic Active Materials and Size-Selective Microporous Polymer Membranes

Patent metadata

Field	Value
Publication number	US-2017346104-A1
Application number	US-201715606961-A
Country	US
Kind code	A1
Filing date	May 26, 2017
Priority date	May 27, 2016
Publication date	Nov 30, 2017
Grant date	—

Abstract

Intermittent energy sources, including solar and wind, require scalable, low-cost, multi-hour energy storage solutions to be effectively incorporated into the grid. Redox-flow batteries offer a solution, but suffer from rapid capacity fade and low Coulombic efficiency due to the high permeability of redox-active species across the battery's membrane. Here we show that active-species crossover can be arrested by scaling the membrane's pore size to molecular dimensions and in turn increasing the size of the active material to be above the membrane's pore-size exclusion limit. When oligomeric redox-active organic molecules were paired with microporous polymer membranes, the rate of active-material crossover was either completely blocked or slowed more than 9,000-fold compared to traditional separators at minimal cost to ionic conductivity. In the case of the latter, this corresponds to an absolute rate of ROM crossover of less than 3 μmol cm −2 day −1 (for a 1.0 M concentration gradient), which exceeds performance targets recently set forth by the battery industry. This strategy was generalizable to both high and low-potential ROMs in a variety of electrolytes, highlighting the importance of macromolecular design in implementing next-generation redox-flow batteries.

First claim

What is claimed is:

1 . A redox flow cell comprising:
at least one redox active organic molecule (ROM) or redox active oligomer (RAO); an electrolyte; and a microporous membrane.

2 . The redox flow cell of claim 1 wherein the undiluted RAO is a liquid.

3 . The redox flow cell of claim 1 wherein the undiluted RAO is an ionic compound.

4 . The redox flow cell of claim 1 wherein the RAO is a monodisperse chemical compound comprising: at least two redox active organic molecules, chosen from nitroxide radicals, nitronylnitroxide radicals, thiazyl radicals, thiafulvalenes, thioethers, thiolanes, thiophenes, viologens, tetraketopiperazines, quinoxalines, triarylamines, diarylalkylamines, quinones, anthraquinones, metallocenes, carbazoles, N-alkylated 4-acylpyridiniums, N-alkylated 4-benzoylpyridiniums, 1,4-dialkoxyl-2,5-dialkylbenzenes, 1,2,3-(dialkylamino)cyclopropeniums, benzofurazans, benzothiadiazoles, nitrobenzenes, and isomers and derivatives thereof; and a chemical scaffold to which the redox active organic molecules are covalently bound, chosen from aliphatic hydrocarbons, cyclic aliphatic hydrocarbons, aromatic hydrocarbons, polycyclic aromatic hydrocarbons, alkylene glycols, alkylene imines, quaternary alkylene iminiums, aliphatic esters, aromatic esters, aliphatic ethers, aromatic ethers, aliphatic thioethers, aromatic thioethers, aliphatic amides, aromatic amides, aliphatic sulfones, aromatic sulfones, and combinations and derivatives thereof.

5 . The redox flow cell of claim 1 wherein the RAO is a polydisperse chemical compound comprising: at least two redox active organic molecules, chosen from nitroxide radicals, nitronylnitroxide radicals, thiazyl radicals, thiafulvalenes, thioethers, thiolanes, thiophenes, viologens, tetraketopiperazines, quinoxalines, triarylamines, diarylalkylamines, quinones, anthraquinones, metallocenes, carbazoles, N-alkylated 4-acylpyridiniums, N-alkylated 4-benzoylpyridiniums, 1,4-dialkoxyl-2,5-dialkylbenzenes, 1,2,3-(dialkylamino)cyclopropeniums, benzofurazans, benzothiadiazoles, nitrobenzenes, and isomers and derivatives thereof; and a chemical scaffold to which the redox active organic molecules are covalently bound, chosen from aliphatic hydrocarbons, cyclic aliphatic hydrocarbons, aromatic hydrocarbons, polycyclic aromatic hydrocarbons, alkylene glycols, alkylene imines, quaternary alkylene iminiums, aliphatic esters, aromatic esters, aliphatic ethers, aromatic ethers, aliphatic thioethers, aromatic thioethers, aliphatic amides, aromatic amides, aliphatic sulfones, aromatic sulfones, and combinations and derivatives thereof.

6 . The chemical scaffold in claim 4 or claim 5 , to which the redox active organic molecules are covalently bound to form a RAO, is linear.

7 . The chemical scaffold in claim 4 or claim 5 , to which the redox active organic molecules are covalently bound to form a RAO, is branched.

8 . The chemical scaffold in claim 4 or claim 5 , to which the redox active organic molecules are covalently bound to form a RAO, is cyclic.

9 . The redox flow cell of claim 1 wherein the ROM or RAO is an ionic compound and used undiluted, or as a solution, dispersion, or suspension in water or an organic solvent.

10 . The redox flow cell of claim 1 wherein the ROM or RAO is used as a solution, dispersion, or suspension in an aqueous or an organic electrolyte.

11 . The redox flow cell of claim 1 wherein the electrolyte is an aqueous or organic solution containing at least one dissolved salt.

12 . The redox flow cell of claim 1 wherein the microporous membrane comprises: a polymer of intrinsic microporosity (PIM), a thermally-rearranged polymer (TR polymer), a metal-organic framework (MOF), a covalent organic framework (COF), a carbon molecular sieve (CMS), a porous coordination polymer (PCP), a microporous 2-dimensional material or atomic layer, or few-layer stacks of one or more types of microporous 2-dimensional materials or atomic layers.

13 . The redox flow cell of claim 7 wherein the microporous membrane is chemically crosslinked.

14 . The redox flow cell of claim 1 wherein the microporous membrane comprises a composite containing at least one of the following: a polymer of intrinsic microporosity (PIM), a thermally-rearranged polymer (TR polymer), a metal-organic framework (MOF), a covalent organic framework (COF), a carbon molecular sieve (CMS), a porous coordination polymer (PCP), a microporous 2-dimensional material or atomic layer, or few-layer stacks of one or more types of microporous 2-dimensional materials or atomic layers.

15 . The redox flow cell of claim 1 wherein the microporous membrane is an unsupported membrane (5 to 500 microns in thickness).

16 . The redox flow cell of claim 1 wherein the microporous membrane is a supported microporous selective layer (0.5 to 500 microns in thickness) comprised of: a selective layer, chosen from a polymer of intrinsic microporosity (PIM), a thermally-rearranged polymer (TR polymer), a metal-organic framework (MOF), a covalent organic framework (COF), a carbon molecular sieve (CMS), a porous coordination polymer (PCP), a microporous 2-dimensional material or atomic layer, or few-layer stacks of one or more types of microporous 2-dimensional materials or atomic layers; or, a chemically crosslinked selective layer incorporating a polymer of intrinsic microporosity (PIM), a thermally-rearranged polymer (TR polymer), a metal-organic framework (MOF), a covalent organic framework (COF), a carbon molecular sieve (CMS), a porous coordination polymer (PCP), a microporous 2-dimensional material or atomic layer, or few-layer stacks of one or more types of microporous 2-dimensional materials or atomic layers; or, a composite selective layer, incorporating at least one polymer of intrinsic microporosity (PIM), thermally-rearranged polymer (TR polymer), metal-organic framework (MOF), covalent organic framework (COF), carbon molecular sieve (CMS), porous coordination polymer (PCP), microporous 2-dimensional material or atomic layer, or few-layer stacks of one or more types of microporous 2-dimensional materials or atomic layers; and where the support is either a porous organic or porous inorganic support; and where the support is coated on a single side or on both sides with the same selective layer or with two different selective layers of the same thickness or of different thickness (0.5 to 500 microns in thickness).

17 . The redox flow cell of claim 1 wherein the microporous membrane reduces the diffusive permeability and rate of crossover of the ROM or RAO between the electrode compartments in the redox flow cell.

18 . The redox flow cell of claim 1 wherein the microporous membrane blocks the diffusive permeability and crossover of the ROM or RAO between the electrode compartments in the redox flow cell.

Assignees

• Univ California

Inventors

• Helms Brett A
• Doris Sean E
• Ward Ashleigh L
• Frischmann Peter D
• Chenard Etienne
• Gavvalapalli Nagarjuna
• Moore Jeffrey S

Classifications

• H01M8/0239 Primary

  Organic resins; Organic polymers · CPC title

• H01M8/188 Primary

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

• Y02E60/50

  Fuel cells · CPC title