Solvent independent reference electrodes for use with non-aqueous electrolytes

Patent metadata

Field	Value
Publication number	US-2022170877-A1
Application number	US-202217673371-A
Country	US
Kind code	A1
Filing date	Feb 16, 2022
Priority date	Jan 4, 2018
Publication date	Jun 2, 2022
Grant date	—

Abstract

The present disclosure relates to a method for forming a reference electrode for use in electrochemical testing applications. The method may involve positioning a porous frit against one end of a hollow tube, and securing the frit and the hollow tube to one another to form an assembly. The method may further involve forming a silver sulfide coating on a silver wire to produce a silver sulfide coated silver wire. The method may further involve filling the hollow tube with a non-aqueous solution, and inserting at least a portion of the silver sulfide coated silver wire into the non-aqueous solution in the hollow tube.

First claim

What is claimed is:

1 . A method for forming a reference electrode for use in electrochemical testing applications, the method comprising:
positioning a porous frit against one end of a hollow tube; securing the frit and the hollow tube to one another to form an assembly; forming a silver sulfide coating on a silver wire to produce a silver sulfide coated silver wire; filling the hollow tube with a non-aqueous solution; and inserting at least a portion of the silver sulfide coated silver wire into the non-aqueous solution in the hollow tube.

2 . The method of claim 1 , wherein the securing of the frit and the hollow tube comprises:
arranging a portion of shrink wrap over portions of the frit and the hollow tube; and heating the portion of shrink wrap, the hollow tube and the frit to shrink the shrink wrap onto the portions of the frit and the hollow tube to form an assembly.

3 . The method of claim 1 , wherein the positioning of a frit against one end of a hollow tube comprises positioning a glass frit against one end of a hollow glass tube.

4 . The method of claim 1 , wherein inserting at least a portion of the silver sulfide coated silver wire into the non-aqueous solution in the hollow tube comprises using a silver wire having a thickness of about 0.5 mm, and then coating the silver wire with a silver sulfide coating.

5 . The method of claim 4 , wherein forming the reference electrode comprises forming a reference electrode with a volume of no more than about 0.5 mL.

6 . The method of claim 5 , wherein securing the hollow tube and the frit to form the assembly comprises securing a hollow tube with a diameter of no more than about 4 mm to the frit, and wherein a ratio of the silver wire diameter to the hollow tube diameter is about 1:8.

7 . The method of claim 1 , further comprising:
boiling the assembly in a solution to remove organic contaminants; boiling the assembly in water; and drying the assembly.

8 . The method of claim 7 , wherein boiling the assembly in a solution comprises boiling the assembly in hydrogen peroxide.

9 . The method of claim 7 , wherein drying the assembly comprises drying the assembly in an oven at a temperature of about 140° C.

10 . The method of claim 2 , wherein heating the portion of shrink wrap comprises heating the portion of shrink wrap to a temperature of about 350° C. for two hours.

11 . The method of claim 1 , wherein forming a silver sulfide coating on a silver wire comprises:
placing a quantity of sulfur on a hot plate; arranging a silver wire over the sulfur; and using the hot plate to heat the sulfur to cause sublimation of the sulfur and subsequent reaction with the silver wire, to thus form the silver sulfide coated silver wire.

12 . The method of claim 1 , wherein forming a silver sulfide coating on a silver wire comprises:
placing elemental sulfur powder in a vial; inserting a clean silver wire into the elemental sulfur powder in the vial; leaving the silver wire in contact with the elemental sulfur powder for a period of at least 24 hours to form the silver sulfide coating on the silver wire; and removing the silver wire from the elemental sulfur powder and rinsing the silver sulfide coated silver wire to remove any portion of the elemental sulfur powder that did not react to form the silver sulfide coating.

13 . The method of claim 1 , wherein forming a silver sulfide coating on a silver wire comprises:
exposing a clean silver wire to a hydrogen sulfide atmosphere containing hydrogen sulfide gas; and maintaining the clean silver wire in the hydrogen sulfide atmosphere for at least 10 minutes until a silver sulfide coating has formed on a surface of the clean silver wire.

14 . The method of claim 1 , further comprising:
measuring a stability of the reference electrode by: submerging the reference electrode in an ionic liquid solution that contains a redox active couple; at least one of scanning or cycling a potential in a range where the redox active couple undergoes a redox reaction; measuring a potential of a redox peak throughout multiple potential cycles; and using the potential drift of the redox peak to quantify the stability of the reference electrode.

15 . A method for forming a reference electrode for use in electrochemical testing applications, the method comprising:
positioning a porous frit against one end of a hollow tube, where the hollow tube has a volume of about 0.1-0.5 mL and a diameter of about 4 mm; securing the frit and the hollow tube to one another to form an assembly; forming a silver sulfide coating on a silver wire to produce a silver sulfide coated silver wire, and wherein the silver wire before forming the silver sulfide coating comprises a diameter of about 0.5 mm, to produce a ratio of the silver wire diameter to the hollow tube diameter of about 1:8; filling the hollow tube with a non-aqueous solution; and inserting at least a portion of the silver sulfide coated silver wire into the non-aqueous solution in the hollow tube.

16 . The method of claim 15 , wherein the securing of the frit and the hollow tube comprises:
arranging a portion of shrink wrap over portions of the frit and the hollow tube; and heating the portion of shrink wrap, the hollow tube and the frit to shrink the shrink wrap onto the portions of the frit and the hollow tube to form the assembly.

17 . The method of claim 16 , wherein heating the portion of shrink wrap comprises heating the portion of shrink wrap to a temperature of about 350° C. for two hours.

18 . The method of claim 15 , further comprising:
boiling the assembly in a solution to remove organic contaminants; boiling the assembly in water; and drying the assembly.

19 . The method 18 , wherein boiling the assembly in a solution comprises boiling the assembly in hydrogen peroxide.

20 . The method of claim 15 , wherein drying the assembly comprises drying the assembly in an oven at a temperature of about 140° C.

21 . A method for monitoring a reference fluid in an electrochemical testing application, the method comprising:
securing a frit to one end of a hollow tube to close off one end of the hollow tube and form an assembly; positioning a silver sulfide coated silver wire at least partially within the hollow tube, wherein the silver sulfide coated wire before being coated with silver sulfide has a diameter of about 0.5 mm and the hollow tube has a diameter of about 4 mm, to produce a ratio of the silver wire diameter to the hollow tube diameter of about 1:8; filling the hollow tube with a quantity of a non-aqueous solution, the non-aqueous solution forming a reference fluid; inserting at least a portion of the silver sulfide coated silver wire into the reference fluid contained in the hollow tube; and monitoring a potential difference associated with the reference fluid contained in the assembly during a test or experiment using the silver sulfide coated silver wire.

22 . The method of claim 21 , further comprising:
prior to filling the hollow tube with the non-aqueous solution: boiling the assembly in a solution to remove organic contaminants; boiling the assembly in water; and drying the assembly.

23 . The method of claim 21 , further comprising forming the silver sulfide coated silver wire by:
placing a quantity of sulfur on a hot plate; arranging a silver wire over the sulfur; and using the hot plate to heat the sulfur to cause

Assignees

• L Livermore Nat Security Llc

Inventors

• Horwood Corie
• Stadermann Michael

Classifications

• G01N27/44704

  Details; Accessories · CPC title

• C23C14/0623

  Sulfides, selenides or tellurides · CPC title

• G01N27/301 Primary

  Reference electrodes · CPC title