Molten Inorganic Electrolytes for Low Temperature Sodium Batteries

Patent metadata

Field	Value
Publication number	US-2021075059-A1
Application number	US-201916564751-A
Country	US
Kind code	A1
Filing date	Sep 9, 2019
Priority date	Sep 9, 2019
Publication date	Mar 11, 2021
Grant date	—

Abstract

A molten sodium-based battery comprises a robust, highly Na-ion conductive, zero-crossover separator and a fully inorganic, fully liquid, highly cyclable molten cathode that operates at low temperatures.

First claim

We claim:

1 . An inorganic molten salt catholyte for electrochemical energy storage, comprising at least one sodium halide of the formula NaF, NaCl, NaBr, or NaI mixed with at least one metal halide of the formula MX y , where M=Mg, Ca, Sr, Ba, Nb, Ta, Mo, W, Ga, In, Sn, Sb, or Bi, and X=F, Cl, Br, or I.

2 . The inorganic molten salt catholyte of claim 1 , wherein the inorganic molten salt catholyte comprises at least one sodium halide and at least one gallium halide.

3 . The inorganic molten salt catholyte of claim 2 , wherein the inorganic molten salt catholyte comprises NaI and GaCl 3 .

4 . The inorganic molten salt catholyte of claim 1 , wherein the inorganic molten salt catholyte comprises a binary, ternary, or quaternary mixture of the at least one sodium halide and the at least one metal halide.

5 . The inorganic molten salt catholyte of claim 1 , wherein the inorganic molten salt catholyte further comprises at least one aluminum halide of the formula AlCl 3 , AlBr 3 , or AlI 3 .

6 . The inorganic molten salt catholyte of claim 1 , wherein the inorganic molten salt catholyte is fully liquid at a temperature less than 120° C.

7 . The inorganic molten salt catholyte of claim 1 , wherein the inorganic molten salt catholyte is fully liquid at a temperature less than 100° C.

8 . The inorganic molten salt catholyte of claim 1 , wherein the inorganic molten salt catholyte comprises between 5 and 25 mol % sodium halide.

9 . A low temperature sodium battery, comprising:
an anode current collector, a sodium-based liquid metal anode, a nonporous Na + -conducting separator, an inorganic molten salt catholyte, and an inert cathode current collector.

10 . The low temperature sodium battery of claim 9 , wherein the sodium-based liquid metal anode comprises molten sodium metal or an alloy of sodium and at least one other alkali metal.

11 . The low temperature sodium battery of claim 9 , wherein the nonporous Na + -conducting separator comprises NaSICON, β″-Al 2 O 3 , or a solid Na + conductor, or a composite thereof.

12 . The low temperature sodium battery of claim 11 , wherein the nonporous Na + -conducting separator further comprises an inert material.

13 . The low temperature sodium battery of claim 9 , wherein the inorganic molten salt catholyte comprises at least one sodium halide of the formula NaF, NaCl, NaBr, or NaI, mixed with at least one metal halide of the formula MY X , where M=Mg, Ca, Sr, Ba, Nb, Ta, Mo, W, Ga, In, Sn, Sb, or Bi, and Y=F, Cl, Br, or I.

14 . The low temperature sodium battery of claim 13 , wherein the inorganic molten salt catholyte comprises at least one sodium halide and at least one gallium halide.

15 . The low temperature sodium battery of claim 14 , wherein the inorganic molten salt catholyte comprises NaI and GaCl 3 .

16 . The low temperature sodium battery of claim 13 , wherein the inorganic molten salt catholyte comprises a binary, ternary, or quaternary mixture of the at least one sodium halide and the at least one metal halide.

17 . The low temperature sodium battery of claim 13 , wherein the inorganic molten salt catholyte further comprises at least one aluminum halide salt of the formula AlCl 3 , AlBr 3 , or AlI 3 .

18 . The low temperature sodium battery of claim 13 , wherein the inorganic molten salt catholyte is fully liquid at a temperature less than 120° C.

19 . The low temperature sodium battery of claim 13 , wherein the inorganic molten salt catholyte is fully liquid at a temperature less than 100° C.

20 . The low temperature sodium battery of claim 13 , wherein the mixture comprises between 5 and 25 mol % sodium halide.

21 . The low temperature sodium battery of claim 9 , wherein the inert cathode current collector comprises tungsten.

22 . The low temperature sodium battery of claim 9 , wherein the inert cathode current collector comprises graphite, carbon felt, or a carbon powder.

Assignees

• Nat Tech & Eng Solutions Sandia Llc

Inventors

• Spoerke Erik David
• Percival Stephen
• Small Leo J

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M2300/0054

  Halogenides · CPC title

• H01M50/431

  Inorganic material · CPC title

• H01M10/4235

  Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence) · CPC title

• H01M50/497

  Ionic conductivity · CPC title