US 12,249,716 B2
Acrylic binder for lithium-sulfur secondary battery cathode and use thereof
Jeong Ae Yoon, Daejeon (KR); Yu Mi Kim, Daejeon (KR); Choong Hyeon Lee, Daejeon (KR); Doo Kyung Yang, Daejeon (KR); and Sung Soo Yoon, Daejeon (KR)
Assigned to LG ENERGY SOLUTION, LTD., Seoul (KR)
Appl. No. 16/335,643
Filed by LG CHEM, LTD., Seoul (KR)
PCT Filed Sep. 26, 2017, PCT No. PCT/KR2017/010581
§ 371(c)(1), (2) Date Mar. 21, 2019,
PCT Pub. No. WO2018/056782, PCT Pub. Date Mar. 29, 2018.
Claims priority of application No. 10-2016-0122911 (KR), filed on Sep. 26, 2016.
Prior Publication US 2020/0161658 A1, May 21, 2020
Int. Cl. H01M 4/62 (2006.01); H01M 4/02 (2006.01); H01M 4/36 (2006.01); H01M 4/38 (2006.01); H01M 4/587 (2010.01); H01M 10/052 (2010.01)
CPC H01M 4/622 (2013.01) [H01M 4/364 (2013.01); H01M 4/38 (2013.01); H01M 4/587 (2013.01); H01M 10/052 (2013.01); H01M 2004/028 (2013.01)] 13 Claims
 
1. A composition for forming a cathode active layer of a lithium-sulfur secondary battery, comprising:
an acrylic binder,
a cathode active material, and
a conductive material,
wherein the acrylic binder consists essentially of:
first polymerized units of a first polymerizable monomer having a polar functional group interacting with the cathode active material;
second polymerized units of a second polymerizable monomer having a cross-linkable functional group that is a hydroxyl group, or a carboxy group; and
third polymerized units of at least one alkyl (meth)acrylate,
wherein the cathode active material is a sulfur-carbon composite,
wherein the acrylic binder comprises 40 to 99.5 parts by weight of the first polymerized units, 0.5 to 30 parts by weight of the second polymerized units and 5 to 30 parts by weight of the third polymerized units,
wherein the first polymerizable monomer comprises a polymerizable monomer having an alkylene oxide group,
wherein the second polymerizable monomer having the cross-linkable functional group that is the hydroxyl group is at least one selected from the group consisting of hydroxyalkyl (meth)acrylate, hydroxypolyethylene glycol (meth)acrylate and hydroxypolypropylene glycol (meth)acrylate, and
wherein the polymerizable monomer having the alkylene oxide group is at least one selected from the group consisting of an alkoxy alkyleneglycol (meth)acrylic acid ester, an alkoxy dialkyleneglycol (meth)acrylic acid ester and an alkoxy polyethyleneglycol (meth)acrylic acid ester.