# US 2025/0096322 A1 · Sodium thiophosphate catholytes for nonaqueous flow batteries

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- Number: US 2025/0096322 A1
- Document ID: US20250096322A1
- Status: Published application
- Kind: A1
- Application number: 18/884,288
- Filed: 2024-09-13
- Published: 2025-03-20
- Earliest claimed: 2023-09-14
- Applicants: UT-Battelle, LLC
- Inventors: Ethan C. Self; Michelle L. Lehmann; Ernesto Camilo Zuleta Suarez
- Web page: https://patentgrep.com/patent/US20250096322A1

## CPC

- H01M 10/0567: characterised by the additives
- H01M 4/5825: {Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines}
- H01M 8/188: {by recharging of redox couples containing fluids; Redox flow type batteries}
- H01M 10/052: Li-accumulators
- H01M 10/0569: characterised by the solvents
- H01M 2300/0025: Organic electrolyte
- Y02E 60/50: Fuel cells
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

A sodium thiophosphate composition and method of making the composition are provided. The composition includes a mixture of Na2S, S, and a thiophosphate compound dissolved in an aprotic solvent to form a solvated complex. The solvated complex has a nominal chemical formula Na2PxSy, in which 0.1≤x≤10 and 1≤y<30. A sodium thiophosphate catholyte for nonaqueous redox flow batteries and a nonaqueous redox flow battery including the sodium thiophosphate catholyte are also provided. The sodium thiophosphate catholyte includes the sodium thiophosphate composition.

## Claims

### Claim 1

A sodium thiophosphate composition comprising:
a mixture of Na2S, S, and a thiophosphate compound dissolved in an aprotic solvent to form a solvated complex having a nominal chemical formula Na2PxSy; wherein
0.1≤x≤10; and
1≤y<30.

### Claim 2 (depends on 1)

The sodium thiophosphate composition of claim 1, wherein 0.1≤x<1.

### Claim 3 (depends on 1)

The sodium thiophosphate composition of claim 1, wherein 4<x≤10.

### Claim 4 (depends on 1)

The sodium thiophosphate composition of claim 1, wherein the solvated complex has one of the following nominal chemical formulas: Na2P0.5S7.5, Na2P10/3S28/3, Na2P3S15, or Na2P10S28.

### Claim 5 (depends on 1)

The sodium thiophosphate composition of claim 1, wherein the thiophosphate compound has the chemical formula PaSb; wherein
a=2 or 4; and
b≤10.

### Claim 6 (depends on 5)

The sodium thiophosphate composition of claim 5, wherein the thiophosphate compound is one of P2S5 and P4S10.

### Claim 7 (depends on 1)

The sodium thiophosphate composition of claim 1, wherein the aprotic solvent comprises at least one of the following: glyme (dimethoxyethane), diglyme (bis(2-methoxyethyl) ether), triglyme (1,2-bis(2-methoxyethoxy) ethane), tetraglyme (bis [2-(2-methoxyethoxy)ethyl] ether), propylene carbonate, acetonitrile, tetrahydrofuran, and dioxolane.

### Claim 8 (depends on 7)

The sodium thiophosphate composition of claim 7, wherein the aprotic solvent is diglyme.

### Claim 9 (depends on 1)

The sodium thiophosphate composition of claim 1, wherein a concentration of the solvated complex in the aprotic solvent is greater than or equal to 0.5 m.

### Claim 10 (depends on 1)

A sodium thiophosphate catholyte for a nonaqueous redox flow battery, the sodium thiophosphate catholyte comprising the composition of claim 1.

### Claim 11 (depends on 1)

A nonaqueous redox flow battery including a catholyte comprising the sodium thiophosphate composition of claim 1.

### Claim 12

A method of making a sodium thiophosphate composition, the method comprising:
adding Na2S, S, and a thiophosphate compound to an aprotic solvent; wherein
Na2S, S, and the thiophosphate compound form a solvated complex in the aprotic solvent, the solvated complex having a nominal chemical formula Na2PxSy, in which
0.1≤x≤10; and
1≤y<30.

### Claim 13 (depends on 12)

The method of claim 12, wherein 0.1≤x<1.

### Claim 14 (depends on 12)

The method of claim 12, wherein 4<x≤10.

### Claim 15 (depends on 12)

The method of claim 12, wherein the solvated complex has one of the following nominal chemical formulas: Na2P0.5S7.5, Na2P10/3S28/3, Na2P3S15, or Na2P10S28.

### Claim 16 (depends on 12)

The method of claim 12, wherein the thiophosphate compound has the chemical formula PaSb; wherein
a=2 or 4; and
b≤10.

### Claim 17 (depends on 16)

The method of claim 16, wherein the thiophosphate compound is one of P2S5 and P4S10.

### Claim 18 (depends on 12)

The method of claim 12, wherein the aprotic solvent comprises at least one of the following: glyme (dimethoxyethane), diglyme (bis(2-methoxyethyl) ether), triglyme (1,2-bis(2-methoxyethoxy) ethane), tetraglyme (bis [2-(2-methoxyethoxy)ethyl] ether), propylene carbonate, acetonitrile, tetrahydrofuran, and dioxolane.

### Claim 19 (depends on 12)

The method of claim 12, wherein the aprotic solvent is diglyme.

### Claim 20 (depends on 12)

The method of claim 12, wherein a concentration of the solvated complex in the aprotic solvent is greater than or equal to 0.5 m.