Method to Improve Sodium Electrochemical Interfaces of Sodium Ion-Conducting Ceramics

Patent metadata

Field	Value
Publication number	US-2023207787-A1
Application number	US-202318092373-A
Country	US
Kind code	A1
Filing date	Jan 2, 2023
Priority date	Nov 26, 2019
Publication date	Jun 29, 2023
Grant date	—

Abstract

The present invention is directed to the modification of sodium electrochemical interfaces to improve performance of sodium ion-conducting ceramics in a variety of electrochemical applications. Enhanced mating of the separator-sodium interface by means of engineered coatings or other surface modifications results in lower interfacial resistance and higher performance at increased current densities, enabling the effective operation of molten sodium batteries and other electrochemical technologies at low and high temperatures.

First claim

We claim:

1 . A method to improve a sodium electrochemical interface, comprising:
providing a sodium ion-conducting ceramic; depositing a coating comprising tin, bismuth, lead, antimony, germanium, silicon, or gold on a surface of the sodium ion-conducting ceramic; and forming a sodium ion-conducting sodium-tin, sodium-bismuth, sodium-lead, sodium-antimony, sodium-germanium, sodium-silicon, or sodium-gold intermetallic phase on the surface of the sodium ion-conducting type ceramic by sodium electrochemical reaction, thereby providing a sodium electrochemical interface with improved sodium ion conduction from a sodium source through the sodium ion-conducting ceramic.

2 . The method of claim 1 , wherein the sodium ion-conducting ceramic comprises NaSICON or β″-alumina.

3 . The method of claim 1 , wherein the sodium source comprises sodium metal or a sodium metal alloy.

4 . The method of claim 1 , wherein the step of depositing a coating comprises coating the surface of the sodium ion-conducting ceramic with metallic tin, bismuth, lead, antimony, germanium, silicon, gold or alloy thereof.

5 . The method of claim 1 , wherein the step of depositing a coating comprises coating the surface of the sodium ion-conducting ceramic with non-metallic compound comprising tin, bismuth, lead, antimony, germanium, silicon, gold and chemically reducing the non-metallic compound to a metal.

6 . The method of claim 5 , wherein the non-metallic compound comprises and oxide or sulfide.

7 . The method of claim 6 , wherein the oxide comprises SnO x , SbO x , or GeO x .

8 . The method of claim 1 , wherein the sodium-tin intermetallic phase comprises Na 15 Sn 4 , Na 3 Sn, Na 4 Sn 3 , Na 9 Sn 4 , NaSn 3 , NaSn 4 , NaSn 6 , α-NaSn, or β-NaSn.

9 . The method of claim 1 , wherein the sodium-bismuth intermetallic phase comprises NaBi or Na 3 Bi).

10 . The method of claim 1 , wherein the sodium-lead intermetallic phase comprises Na 15 Pb 9 , Na 5 Pb 2 , NaPb, or NaPb 3 .

11 . The method of claim 1 , wherein the sodium-germanium intermetallic phase comprises NaGe.

12 . The method of claim 1 , wherein the sodium-silicon intermetallic phase comprises NaSi.

13 . The method of claim 1 , wherein the sodium-antimony intermetallic phase comprises Na 3 Sb or NaSb.

14 . The method of claim 1 , wherein the sodium-gold intermetallic phase comprises Au 5 Na, Au 2 Na, AuNa, AuNa 2 .

15 . The method of claim 1 , wherein the intermetallic phase comprises an intermetallic alloy phase.

16 . The method of claim 15 , wherein the intermetallic alloy phase comprises Na 5 SnSb 3 or Na 8 SnSb 4 .

17 . The method of claim 15 , wherein the intermetallic alloy phase comprises an antimony-transition metal intermetallic phase.

18 . The method of claim 17 , wherein the antimony-transition metal intermetallic phase comprises Na x CoSb, Na x SnSb, Na x Cu 2 Sb, Na x Cu 11 Sb 3 , Na x NiSb, or Na x Zn 4 Sb 3 .

19 . The method of claim 15 , wherein the intermetallic alloy phase comprises a gold-transition metal intermetallic phase.

20 . The method of claim 19 , wherein the gold-transition metal intermetallic alloy phase comprises Na, Au, and Mg, Al, Zn, Cd, Pb, Cd, Tl, Ge, Sn, or Ga.

21 . A method to improve a sodium electrochemical interface, comprising:
providing a sodium ion-conducting ceramic; modifying the material structure of a surface or bulk of the sodium ion-conducting ceramic to include tin, bismuth, lead, antimony, germanium, silicon, or gold; and forming a sodium ion-conducting sodium-tin, sodium-bismuth, sodium-lead, sodium-antimony, sodium-germanium, sodium-silicon, or sodium-gold intermetallic phase on the surface of the sodium ion-conducting type ceramic by sodium electrochemical reaction, thereby providing a sodium electrochemical interface with improved sodium ion conduction from a sodium source through the sodium ion-conducting ceramic.

Assignees

• Nat Tech & Eng Solutions Sandia Llc

Inventors

• Spoerke Erik David
• Gross Martha
• Percival Stephen
• Small Leo J

Classifications

• H01M4/48

  of inorganic oxides or hydroxides · CPC title

• H01M10/24 Primary

  Alkaline accumulators · CPC title

• H01M4/0402

  Methods of deposition of the material · CPC title

• H01M4/381 Primary

  Alkaline or alkaline earth metals elements (H01M4/40 takes precedence) · CPC title

• H01M4/366

  as layered products · CPC title