Cathode for lithium-sulfur battery and manufacturing method therefor

Patent metadata

Field	Value
Publication number	US-10170766-B2
Application number	US-201414908331-A
Country	US
Kind code	B2
Filing date	Jul 8, 2014
Priority date	Aug 1, 2013
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

The present application relates to a cathode for a lithium-sulfur battery and a method of preparing the same. More specifically, the cathode for a lithium-sulfur battery according to an exemplary embodiment of the present application includes: a cathode active part including a sulfur-carbon composite; and a cathode coating layer including an amphiphilic polymer provided on at least one portion of a surface of the cathode active part and including a hydrophilic portion and a hydrophobic portion.

First claim

The invention claimed is:

1. A cathode for a lithium-sulfur battery, comprising:
a cathode active part comprising a sulfur-carbon composite; and
a cathode coating layer provided on at least one portion of a surface of the cathode active part and consisting of an amphiphilic polymer comprising polyvinyl pyrrolidone (PVP), said amphiphilic polymer including a hydrophilic portion and a hydrophobic portion,
wherein the cathode coating layer comprises pores and the pores have an average diameter of 1 nm to 10 μm,
wherein the cathode coating layer has a porosity of 50 to 95% based on a total volume of the cathode coating layer, and
wherein the cathode coating layer has a thickness of 10 nm to 1 μm.

2. The cathode for a lithium-sulfur battery of claim 1 , wherein a hydrophobic portion of the amphiphilic polymer is oriented toward the sulfur-carbon composite.

3. The cathode for a lithium-sulfur battery of claim 1 , wherein a content of the amphiphilic polymer is 0.01 to 10 parts by weight based on 100 parts by weight of the sulfur-carbon composite of the cathode active part.

4. The cathode for a lithium-sulfur battery of claim 1 , wherein the cathode coating layer is provided over an entire portion of a surface of the cathode active part.

5. The cathode for a lithium-sulfur battery of claim 1 , wherein the sulfur-carbon composite is formed by applying sulfur particles on porous carbon.

6. The cathode for a lithium-sulfur battery of claim 1 , wherein the sulfur-carbon composite is formed by dissolving sulfur particles and mixing the sulfur particles with carbon.

7. The cathode for a lithium-sulfur battery of claim 1 , wherein the cathode active part further comprises one or more additives selected from a transition metal element, a Group IIIA element, a Group IVA element, a sulfur compound of these elements, and an alloy of these elements and sulfur.

8. A lithium-sulfur battery comprising:
an anode comprising lithium metal or a lithium alloy as an anode active material;
the cathode for a lithium-sulfur battery of claim 1 ;
a separator provided between the cathode and the anode; and
an electrolyte impregnated in the anode, the cathode, and the separator and comprising a lithium salt and an organic solvent.

9. The lithium-sulfur battery of claim 8 , wherein the lithium salt is one or more selected from the group consisting of LiSCN, LiBr, LiI, LiPF 6 , LiBF 4 , LiSO 3 CF 3 , LiClO 4 , LiSO 3 CH 3 , LiB(Ph) 4 , LiC(SO 2 CF 3 ) 3 , and LiN(SO 2 CF 3 ) 2 .

10. The lithium-sulfur battery of claim 8 , wherein the lithium alloy is an alloy of lithium and a metal selected from the group consisting of Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Al, and Sn.

11. The lithium-sulfur battery of claim 8 , wherein the organic solvent is a single solvent or a mixed organic solvent of two or more solvents.

12. A battery module comprising the lithium-sulfur battery of claim 8 as a unit cell.

Assignees

• Lg Chemical Ltd

Inventors

• Son Byoungkuk
• Jang Minchul
• Kim Min Seo
• Sung Da Young
• Lee Seong Ho

Classifications

• H01M10/0568

  characterised by the solutes · CPC title

• H01M4/62

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title

• H01M4/136 Primary

  Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title

• H01M2220/30

  Batteries in portable systems, e.g. mobile phone, laptop · CPC title