Lithium-sulfur battery with lithium polysulfide catholyte

Patent metadata

Field	Value
Publication number	US-10777811-B2
Application number	US-201815910802-A
Country	US
Kind code	B2
Filing date	Mar 2, 2018
Priority date	Mar 2, 2018
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

A liquid catholyte for a Li—S battery comprises a non-aqueous solution of at least one lithium polysulfide of formula Li 2 S x (wherein x is selected from 4, 6, and 8) and an anion receptor compound capable of complexing with polysulfide anion. The non-aqueous solution typically is composed of the Li 2 S x and the anion receptor compound dissolved in a non-aqueous solvent (e.g., one or more organic ether or fluorinated ether solvents). The anion receptor compound typically is present in the catholyte at a concentration of about 0.1 M to about 4 M. Li—S batteries comprise a metallic lithium anode; a porous conductive substrate; a separator membrane between the anode and the porous conductive substrate; and the liquid catholyte composition within pores of the substrate.

First claim

The invention claimed is:

1. A liquid catholyte composition for a lithium-sulfur (Li—S) battery, the catholyte comprising: a non-aqueous solution of at least one lithium polysulfide of formula Li 2 S x and an anion receptor compound capable of complexing with polysulfide anion; wherein x is selected from 4, 6, and 8; the anion receptor compound comprises a boron compound of formula B(X) 3 , wherein each X independently is an unsubstituted C 1 to C 6 alkyl.

2. The composition of claim 1 , wherein the non-aqueous solution comprises at least one solvent selected from the group consisting of an organic ether and a fluorinated organic ether.

3. The composition of claim 2 , wherein the organic ether solvent comprises at least one solvent selected from the group consisting of 1,3-dioxolane and 1,2-dimethoxyethane.

4. The composition of claim 1 , wherein each X is identical.

5. The composition of claim 1 , wherein the anion receptor compound is B(CH 2 CH 3 ) 3 .

6. The composition of claim 1 , wherein the non-aqueous solution further comprises another soluble lithium salt in addition to the lithium polysulfide.

7. The composition of claim 1 , wherein the anion receptor compound is present in the solution at a concentration in the range of about 0.1 molar (M) to about 4 M.

8. The composition of claim 1 , wherein the lithium polysulfide is present in the solution at a concentration in the range of about 0.5 M to about 16 M on an elemental sulfur basis.

9. The composition of claim 1 , wherein each X independently is selected from the group consisting of methyl and ethyl.

10. A lithium-sulfur (Li—S) battery comprising:
(a) an anode comprising metallic lithium;
(b) a porous conductive substrate;
(c) a separator membrane between and contacting the anode and the porous conductive substrate; and
(d) a liquid catholyte composition within pores of the porous conductive substrate; wherein the catholyte solution comprises a non-aqueous solution of at least one lithium polysulfide of formula Li 2 S x and an anion receptor compound capable of complexing with polysulfide anion; wherein x is selected from 4, 6, and 8; the anion receptor compound comprises a boron compound of formula B(X) 3 , wherein each X independently is an unsubstituted C 1 to C 6 alkyl.

11. The battery of claim 10 , wherein the non-aqueous solution comprises at least one solvent selected from the group consisting of an organic ether and a fluorinated organic ether.

12. The battery of claim 11 , wherein the organic ether solvent comprises at least one solvent selected from the group consisting of 1,3-dioxolane and 1,2-dimethoxyethane.

13. The battery of claim 10 , wherein the non-aqueous solution further comprises another soluble lithium salt in addition to the lithium polysulfide.

14. The battery of claim 10 , wherein the anion receptor compound is present in the solution at a concentration in the range of about 0.1 M to about 4 M.

15. The battery of claim 10 , wherein the lithium polysulfide is present in the solution at a concentration in the range of about 0.5 M to about 16 M on an elemental sulfur basis.

16. The battery of claim 10 , wherein the porous conductive substrate comprises a porous carbon material.

17. The battery of claim 10 , wherein the porous separator membrane comprises a layer of a porous polyolefin membrane and a layer of a LISICON ceramic membrane.

Assignees

• Uchicago Argonne Llc

Inventors

• Zhang Zhengcheng
• Xue Zheng
• Zhao Feng

Classifications

• H01M50/451

  comprising layers of only organic material and layers containing inorganic material · CPC title

• H01M50/417

  Polyolefins · CPC title

• H01M50/434

  Ceramics · CPC title

• H01M10/0567

  characterised by the additives · CPC title

• H01M10/0568

  characterised by the solutes · CPC title