Method of reducing vanadium pentoxide to vanadium(III) oxide

Patent metadata

Field	Value
Publication number	US-9525164-B1
Application number	US-201615142965-A
Country	US
Kind code	B1
Filing date	Apr 29, 2016
Priority date	Apr 29, 2016
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

A method for producing pure vanadium(III) oxide and a vanadyl sulfate solution comprising contacting vanadium pentoxide with a solid inorganic reducing agent. The resultant mixture containing a mix of vanadium oxides is leached with sulfuric acid to form vanadium(III) oxide and vanadyl sulfate.

First claim

The invention claimed is:

1. A method for producing vanadium trioxide, comprising:
reacting solid vanadium pentoxide with a solid inorganic reducing agent to form a mixture;
mixing sulfuric acid with the mixture to form a suspension comprising vanadium trioxide and vanadyl sulfate; and
filtering the suspension to obtain solid vanadium trioxide and a solution of vanadyl sulfate.

2. The method of claim 1 , wherein the solid vanadium pentoxide and the solid inorganic reducing agent are reacted in the absence of solvent.

3. The method of claim 1 , wherein the reacting comprises heating for 10-20 hours at a temperature ranging from 300° C. to less than 400° C.

4. The method of claim 3 , wherein the reacting comprises heating for 10 hours at a temperature ranging from 300° C. to less than 330° C.

5. The method of claim 1 , wherein the reacting comprises mixing the solid vanadium pentoxide with the solid inorganic reducing agent, followed by heating for 10-20 hours at a temperature ranging from 300° C. to less than 400° C.

6. The method of claim 1 , wherein the solid inorganic reducing agent comprises a borohydride anion or a derivative thereof.

7. The method of claim 1 , wherein the solid inorganic reducing agent is at least one of sodium borohydride and potassium borohydride.

8. The method of claim 1 , wherein the solid inorganic reducing agent is sodium borohydride.

9. The method of claim 1 , wherein a molar ratio of vanadium pentoxide to a total number of hydrogen atoms in the solid inorganic reducing agent ranges from 1:4 to 1:20.

10. The method of claim 1 , wherein a molar ratio of vanadium pentoxide to a total number of hydrogen atoms in the solid inorganic reducing agent is about 1:8.

11. The method of claim 1 , wherein the sulfuric acid has a concentration ranging from 6-18 M.

12. The method of claim 1 , wherein the mixing is carried out at a temperature ranging from 15-30° C.

13. The method of claim 1 , wherein the sulfuric acid and the mixture are mixed by sonication or stirring.

14. The method of claim 1 , further comprising cooling the mixture to a temperature ranging from −10° C. to 5° C. prior to the mixing to form a cooled mixture.

15. The method of claim 1 , further comprising allowing the suspension to stand for 4-10 hours prior to the filtering.

16. The method of claim 1 , which produces solid vanadium trioxide with a purity of at least 95%.

17. A method for producing vanadium trioxide, comprising:
reacting solid vanadium pentoxide with a solid inorganic reducing agent comprising a borohydride anion or a derivative thereof to form a mixture, wherein the solid inorganic reducing agent is supported on a polymer or is in the form of a neat solid;
mixing sulfuric acid with the mixture to form a suspension comprising vanadium trioxide and vanadyl sulfate; and
filtering the suspension to obtain solid vanadium trioxide and a solution of vanadyl sulfate.

18. A method for making an electrode, comprising:
reacting solid vanadium pentoxide with a solid inorganic reducing agent to form a mixture;
mixing sulfuric acid with the mixture to form a suspension comprising vanadium(III) oxide and vanadyl sulfate;
filtering the suspension to obtain solid vanadium(III) oxide and a solution of vanadyl sulfate;
mixing the solid vanadium(III) oxide with a polymer and an electroconductive carbon material to form a slurry;
applying the slurry as a coating onto a metal foil; and
drying the coating to form the electrode.

19. The method of claim 18 , wherein the slurry is applied on the metal foil with a roll coater.

Assignees

• Univ King Abdulaziz

Inventors

• Aksu Mecit
• Al-Zain Omar Ali

Classifications

• H01M4/0404 Primary

  by coating on electrode collectors · CPC title

• C01G31/02

  Oxides · CPC title

• H01M4/0416

  involving impregnation with a solution, dispersion, paste or dry powder (H01M4/0438 takes precedence) · CPC title

• H01M4/0497 Primary

  Chemical precipitation · CPC title

• H01M2004/028

  Positive electrodes · CPC title