Single lithium ion conductor as binder in lithium-sulfur or silicon-sulfur battery

Patent metadata

Field	Value
Publication number	US-9537144-B2
Application number	US-201313836101-A
Country	US
Kind code	B2
Filing date	Mar 15, 2013
Priority date	Mar 15, 2013
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

A sulfur-containing electrode has a binder comprising a single-lithium ion conductor. The electrode may be used a cathode in a lithium-sulfur or silicon-sulfur battery.

First claim

What is claimed is:

1. A sulfur cathode comprising:
a porous conductive carbonaceous material infiltrated with sulfur that has a crown S 8 elemental form and is transitionable to an intermediate polysulfide compound having a structure represented by Li 2 S n , wherein 2≦n≦8, via two-electron reduction; and
a binder binding together and at least partially encapsulating the porous conductive carbonaceous material and the sulfur to form a physical barrier which at least partially prevents diffusion of the intermediate polysulfide compound from the sulfur cathode;
wherein the binder includes a polymer that is a single-lithium ion conductor formed from a polymeric anion having associated lithium cations;
wherein the polymeric anion having associated lithium cations is a polymer having a polysulfone backbone and pendent lithium bis(trifluoromethanesulfonyl)imide groups.

2. The sulfur cathode according to claim 1 , wherein the polymeric anion having associated lithium cations is present in the sulfur cathode in an amount of from about 0.1 parts by weight to about 60 parts by weight based on 100 parts by weight of the sulfur cathode.

3. The sulfur cathode according to claim 1 , wherein the polymeric anion having associated lithium cations is present in the binder in an amount of from about 5 parts by weight to about 100 parts by weight based on 100 parts by weight of the binder.

4. A method of forming a sulfur cathode, the method comprising:
forming a porous conductive carbonaceous material;
infiltrating the porous conductive carbonaceous material with molten sulfur that has a crown S 8 elemental form and is transitionable to an intermediate polysulfide compound having a structure represented by Li 2 S n , wherein 2≦n≦8, via two-electron reduction to form a precursor;
mixing the precursor with a binder comprising a polymer that is a single-lithium ion conductor formed from a polymeric anion having associated lithium cations to form a slurry; and
slot die coating the slurry onto a current collector to thereby form the sulfur cathode;
wherein the binder binds together and at least partially encapsulates the porous conductive carbonaceous material and the sulfur to form a physical barrier which at least partially prevents diffusion of the intermediate polysulfide compound from the sulfur cathode;
wherein mixing includes incorporating the polymeric anion having associated lithium cations with the precursor so that the polymeric anion having associated lithium cations is present in the sulfur cathode in an amount of from about 2 parts by weight to about 40 parts by weight based on 100 parts by weight of the sulfur cathode;
wherein the polymeric anion having associated lithium cations is a polymer having a polysulfone backbone with pendent lithium bis(trifluoromethanesulfonyl)imide groups.

5. The method according to claim 4 , wherein mixing includes incorporating the polymeric anion having associated lithium cations with the precursor so that the polymeric anion having associated lithium cations is present in the binder in an amount of from about 5 parts by weight to about 100 parts by weight based on 100 parts by weight of the binder.

6. The method according to claim 4 , wherein mixing includes incorporating the precursor with the binder, wherein the binder comprises only one polymeric anion having associated lithium cations.

7. A battery comprising:
(a) a sulfur cathode comprising:
a porous conductive carbonaceous material infiltrated with sulfur that has a crown S 8 elemental form and is transitionable to an intermediate polysulfide compound having a structure represented by Li 2 S n , wherein 2≦n≦8, via two-electron reduction; and
a binder binding together and at least partially encapsulating the porous conductive carbonaceous material and the sulfur to form a physical barrier which at least partially prevents diffusion of the intermediate polysulfide compound from the sulfur cathode;
wherein the binder includes a polymer that is a single-lithium ion conductor formed from a polymeric anion having associated lithium cations;

(b) an anode comprising lithium or a lithium compound;
(c) a separator disposed between and separating the sulfur cathode and the anode; and
(d) an electrolyte solution contacting the anode and the sulfur cathode and comprising a nonaqueous solution of lithium salts;
wherein the polymeric anion having associated lithium cations is a polymer having a polysulfone backbone with pendent lithium bis(trifluoromethanesulfonyl)imide groups.

8. The battery according to claim 7 , wherein the binder includes only one polymer.

9. A method of operating a device, the method comprising providing electricity to the device from the battery according to claim 7 .

10. The method of claim 9 , wherein the device is an automotive vehicle.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Huang Xiaosong
• Cai Mei
• Verbrugge Mark W
• Yang Li

Classifications

• H01M4/623

  fluorinated polymers · CPC title

• H01M4/364 Primary

  as mixtures · CPC title

• H01M4/604

  containing aliphatic main chain polymers · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H02J7/00

  Circuit arrangements for charging or discharging batteries or for supplying loads from batteries · CPC title