Neutral zinc iron flow battery and use thereof

Patent metadata

Field	Value
Publication number	US-2023246216-A1
Application number	US-202118010711-A
Country	US
Kind code	A1
Filing date	Mar 26, 2021
Priority date	Jul 6, 2020
Publication date	Aug 3, 2023
Grant date	—

Abstract

The invention relates to the field of flow batteries, and in particular relates to a neutral zinc iron flow battery and the use thereof. The neutral zinc iron flow battery comprises a negative electrode electrolyte solution and a positive electrode electrolyte solution, wherein a negative electrode electrolyte in the negative electrode electrolyte solution comprises a first ferrous salt and a zinc salt, the molar ratio of the first ferrous salt to the zinc salt is 0.01 to 0.25:1, wherein the first ferrous salt is based on Fe2−, and the zinc salt is based on Zn2+. By doping the first ferrous salt in the negative electrode electrolyte solution and defining the molar ratio of the first ferrous salt to the zinc salt, the concentration of the negative electrode electrolyte active material is increased, the permeation of the positive electrode ferrous ions is reduced, and the stability of the negative electrode electrolyte solution is improved; moreover, the negative electrode electrolyte solution delays the generation of zinc dendrites and improves the energy density and cycle stability of the neutral zinc iron flow battery.

First claim

1 . A neutral zinc iron flow battery, characterized in that the neutral zinc iron flow battery comprises a negative electrode electrolyte solution and a positive electrode electrolyte solution, wherein a negative electrode electrolyte in the negative electrode electrolyte solution comprises a first ferrous salt and zinc salt, the molar ratio of the first ferrous salt to the zinc salt is 0.01-0.25:1, wherein the first ferrous salt is based on Fe 2+ and the zinc salt is based on Zn 2+ .

2 . The neutral zinc iron flow battery according to claim 1 , wherein, the molar ratio of the first ferrous salt to the zinc salt is 0.02-0.1:1, wherein the first ferrous salt is based on Fe 2+ and the zinc salt is based on Zn 2+ ;
preferably, based on the negative electrode electrolyte solution, the concentration of the first ferrous salt is 0.01-0.05 mol/L, preferably 0.05-0.3 mol/L.

3 . The neutral zinc iron flow battery according to claim 1 , wherein the first ferrous salt is selected from at least one of ferrous sulfate, ferrous chloride and ferrous bromide, preferably from ferrous sulfate and/or ferrous chloride;
preferably, the zinc salt is selected from at least one of zinc chloride, zinc sulfate and zinc bromide, preferably from zinc chloride and/or zinc sulfate.

4 . The neutral zinc iron flow battery according to claim 1 , wherein the negative electrode electrolyte also comprises a first supporting electrolyte and/or a first additive;
preferably, based on the negative electrode electrolyte solution, the concentration of the first supporting electrolyte is 0.5-10 mol/L, preferably 1-5 mol/L; preferably, based on the negative electrode electrolyte solution, the concentration of the first additive is 0.01-5 mol/L, preferably 0.1-3 mol/L.

5 . The neutral zinc iron flow battery according to claim 4 , wherein the first supporting electrolyte is selected from at least one of potassium chloride, potassium sulfate, potassium nitrate, ammonium chloride, ammonium sulfate, sodium chloride and sodium sulfate;
preferably, the first additive is selected from at least one of sodium citrate, glycine, lysine, sucrose, gelatin, ascorbic acid and DMSO.

6 . The neutral zinc iron flow battery according to any of claims claim 1 , wherein the positive electrode electrolyte in the positive electrode electrolyte solution comprises a second ferrous salt and an optional ferric salt;
preferably, the molar ratio of the second ferrous salt to the ferric salt is 1-10:0-5, preferably 3-10:1-5, wherein the second ferrous salt is based on Fe 2+ and the ferric salt is based on Fe + ; preferably, based on the positive electrode electrolyte solution, the concentration of the second ferrous salt is 0.1-3 mol/L, preferably 0.5-2 mol/L.

7 . The neutral zinc iron flow battery according to claim 6 , wherein the second ferrous salt is selected from at least one of ferrous sulfate, ferrous chloride and ferrous bromide, preferably from ferrous sulfate and/or ferrous chloride;
preferably, the ferric salt is selected from at least one of ferric sulfate, ferric chloride and ferric nitrate.

8 . The neutral zinc iron flow battery according to claim 6 , wherein the positive electrode electrolyte also comprises a second supporting electrolyte and/or a second additive;
preferably, based on the positive electrode electrolyte solution, the concentration of the second supporting electrolyte is 0.5-10 mol/L, preferably 0.5-3 mol/L; preferably, based on the positive electrode electrolyte solution, the concentration of the second additive is 0.1-5 mol/L, preferably 0.1-3 mol/L; preferably, the second supporting electrolyte is selected from at least one of potassium chloride, potassium sulfate, potassium nitrate, ammonium chloride, ammonium sulfate, sodium chloride and sodium sulfate; preferably, the second additive is selected from at least one of sodium citrate, glycine, lysine, sucrose, gelatin, ascorbic acid and DMSO.

9 . The neutral zinc iron flow battery according to claim 1 , wherein the neutral zinc iron flow battery also comprises a pretreated electrode and a pretreated separator;
preferably, the pretreatment of the electrode comprises: soaking the electrode in acid solution and then carrying out calcination, wherein the calcination is carried out in air or the gas mixture containing NH 3 and/or PH 3 and inert gas; preferably, the pretreatment of the separator comprises: soaking the separator in acid solution and the positive electrode electrolyte solution sequentially, and then washing the separator with deionized water.

10 . A method of using the neutral zinc iron flow battery according to claim 1 in renewable energy generation and storage, emergency power system, reserve power station and power system peak cut.

11 . The neutral zinc iron flow battery according to claim 7 , wherein the positive electrode electrolyte also comprises a second supporting electrolyte and/or a second additive;
preferably, based on the positive electrode electrolyte solution, the concentration of the second supporting electrolyte is 0.5-10 mol/L, preferably 0.5-3 mol/L; preferably, based on the positive electrode electrolyte solution, the concentration of the second additive is 0.1-5 mol/L, preferably 0.1-3 mol/L; preferably, the second supporting electrolyte is selected from at least one of potassium chloride, potassium sulfate, potassium nitrate, ammonium chloride, ammonium sulfate, sodium chloride and sodium sulfate; preferably, the second additive is selected from at least one of sodium citrate, glycine, lysine, sucrose, gelatin, ascorbic acid and DMSO.

Assignees

• China Energy Investment Corp Ltd
• Nat Lnstitute Of Clean And Low Carbon Energy

Inventors

• Wang Rui
• Yao Zhen
• Liu Qinghua

Classifications

• H01M8/188 Primary

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

• H01M2250/10

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

• H01M8/08

  Fuel cells with aqueous electrolytes · CPC title

• H01M2300/0002

  Aqueous electrolytes · CPC title

• H01M2220/10

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