Electrolyte for flow battery and flow battery system

Patent metadata

Field	Value
Publication number	US-11233253-B2
Application number	US-201716319186-A
Country	US
Kind code	B2
Filing date	May 17, 2017
Priority date	Jul 26, 2016
Publication date	Jan 25, 2022
Grant date	Jan 25, 2022

Abstract

Provided is an electrolyte for a flow battery, the electrolyte being supplied to a flow battery, in which a total concentration of ions of elements of groups 1 to 8 and ions of elements of groups 13 to 16 in the fifth period of the periodic table, and ions of elements of groups 1, 2, and 4 to 8 and ions of elements of groups 13 to 15 in the sixth period of the periodic table, the ions being impurity element ions involved in generation of a gas containing elemental hydrogen, is 610 mg/L or less, a concentration of vanadium ions is 1 mol/L or more and 3 mol/L or less, a concentration of free sulfuric acid is 1 mol/L or more and 4 mol/L or less, a concentration of phosphoric acid is 1.0×10 −4 mol/L or more and 7.1×10 −1 mol/L or less, a concentration of ammonium is 20 mg/L or less, and a concentration of silicon is 40 mg/L or less. When a charging and discharging test is performed by circulating and supplying the electrolyte to the flow battery under specific conditions, a generation rate of hydrogen is less than 10 cc/h/m 2 and a generation rate of hydrogen sulfide is less than 5.0×10 −3 cc/h/m 2 , the hydrogen and the hydrogen sulfide being generated in a negative electrode of the flow battery during charging and discharging.

First claim

The invention claimed is:

1. An electrolyte for a flow battery, the electrolyte being supplied to a flow battery,
wherein a total concentration of impurity element ions of groups 1 to 8 and impurity element ions of groups 13 to 16 in the fifth period of the periodic table, and impurity element ions of groups 1, 2, and 4 to 8 and impurity element ions of groups 13 to 15 in the sixth period of the periodic table, the ions being impurity element ions involved in generation of a gas containing elemental hydrogen, is 610 mg/L or less,
a concentration of vanadium ions is 1 mol/L or more and 3 mol/L or less,
a concentration of free sulfuric acid is 1 mol/L or more and 4 mol/L or less,
a concentration of phosphoric acid is 1.0×10 −4 mol/L or more and 7.1×10 −1 mol/L or less,
a concentration of ammonium is 20 mg/L or less,
a concentration of silicon is 40 mg/L or less,
a concentration of barium ions, which are among the impurity element ions involved in generation of the gas containing elemental hydrogen, is 2 mg/L or more and 20 mg/L or less,
a concentration of tungsten ions, which are among the impurity element ions involved in generation of the gas containing elemental hydrogen, is 2 mg/L or more and 30 mg/L or less, and
a concentration of rhenium ions, which are among the impurity element ions involved in generation of the gas containing elemental hydrogen, is 1 mg/L or more and 5 mg/L or less, and
when a charging and discharging test is performed by circulating and supplying the electrolyte to the flow battery under conditions below, a generation rate of hydrogen is less than 10 cc/h/m 2 and a generation rate of hydrogen sulfide is less than 5.0×10 −3 cc/h/m 2 , the hydrogen and the hydrogen sulfide being generated in a negative electrode of the flow battery during charging and discharging,
Charge and discharge method: continuous charging and discharging at constant current;
Current density: 70 (mA/cm 2 );
End-of-charge voltage: 1.55 (V)/cell;
End-of-discharge voltage: 1.00 (V)/cell; and
Temperature: room temperature (25° C.).

2. The electrolyte for a flow battery according to claim 1 , wherein a concentration of molybdenum ions, which are impurity element ions involved in generation of a gas containing elemental hydrogen, is 510 mg/L or less.

3. The electrolyte for a flow battery according to claim 1 , wherein a concentration of indium ions, which are impurity element ions involved in generation of a gas containing elemental hydrogen, is 5 mg/L or less.

4. The electrolyte for a flow battery according to claim 1 , wherein a concentration of antimony ions, which are impurity element ions involved in generation of a gas containing elemental hydrogen, is 10 mg/L or less.

5. The electrolyte for a flow battery according to claim 1 , wherein a concentration of bismuth ions, which are impurity element ions involved in generation of a gas containing elemental hydrogen, is 20 mg/L or less.

6. A flow battery system comprising the electrolyte for a flow battery according to claim 1 , and a flow battery to which the electrolyte for a flow battery is supplied.

7. The flow battery system according to claim 6 , wherein the flow battery system can be used as a storage battery.

8. The flow battery system according to claim 6 , wherein the impurity element ions involved in generation of a gas containing elemental hydrogen is adjusted to 610 mg/L or less before operation of the flow battery system.

9. The flow battery system according to claim 6 , wherein the impurity element ions involved in generation of a gas containing elemental hydrogen is adjusted to 610 mg/L or less within a short period of use after the start of operation of the flow battery system.

10. The flow battery system according to claim 6 , wherein the impurity element ions involved in generation of a gas containing elemental hydrogen is adjusted to 610 mg/L or less within 100 cycles in a battery with a capacity of 10 kWh or more after the start of operation of the flow battery system.

11. The flow battery system according to claim 6 , wherein the impurity element ions involved in generation of a gas containing elemental hydrogen is adjusted to 610 mg/L or less at any time during the operation of the flow battery system.

12. The electrolyte for a flow battery according to claim 1 , wherein the ions being impurity element ions involved in generation of a gas containing elemental hydrogen, is 550 mg/L or less.

13. The electrolyte for a flow battery according to claim 1 , wherein the ions being impurity element ions involved in generation of a gas containing elemental hydrogen, is 500 mg/L or less.

14. The flow battery system ccording to claim 6 , wherein the impurity element ions involved in generation of a gas containing elemental hydrogen are removed from the electrolyte through one or more of, coagulating sedimentation, solvent extraction, filtration with an ion-exchange resin or a chelate resin, electrolytic deposition and membrane separation.

15. The flow battery system according to claim 6 , wherein the impurity element ions involved in generation of a gas containing elemental hydrogen are removed from the electrolyte during a waiting period or stop period during the operation of the flow battery.

Assignees

• Sumitomo Electric Industries

Inventors

• Moriuchi Kiyoaki
• Sekine Ryojun
• Sugihara Takayasu

Classifications

• Y02B90/10

  Applications of fuel cells in buildings · CPC title

• H01M2250/10

  Fuel cells in stationary systems, e.g. emergency power source in plant · CPC title

• H01M8/188 Primary

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

• H01M8/04746

  Pressure; Flow · CPC title

• H01M8/04231

  Purging of the reactants · CPC title