Binder composition for secondary batteries, and electrode and lithium secondary battery including the same

Patent metadata

Field	Value
Publication number	US-11223046-B2
Application number	US-201615516820-A
Country	US
Kind code	B2
Filing date	Jun 16, 2016
Priority date	Jun 17, 2015
Publication date	Jan 11, 2022
Grant date	Jan 11, 2022

Abstract

Disclosed is a binder composition for secondary batteries including composite latex comprising conjugated diene latex particles (A) and copolymer latex particles (B), each present in an independent phase, wherein the composite latex has a pH of 7 or less.

First claim

The invention claimed is:

1. A binder composition for secondary batteries comprising a composite latex comprising conjugated diene latex particles (A) and copolymer latex particles (B), each present in an independent phase,
wherein the conjugated diene latex particles (A) comprise a polymer of:
(a) a conjugated diene monomer or a conjugated diene polymer, and one or more monomers selected from the group consisting of:
(b) one or more monomers selected from the group consisting of acrylate, vinyl, (meth)acrylamide and nitrile monomers;
(c) an unsaturated carboxylic acid monomer; and
(d) a hydroxyl group-containing monomer;

wherein the copolymer latex particles (B) comprise a polymer of:
(a) a (meth)acrylic acid ester monomer, and one or more monomers selected from the group consisting of:
(b) one or more monomers selected from the group consisting of acrylate, vinyl, (meth)acrylamide and nitrile monomers;
(c) an unsaturated carboxylic acid monomer; and
(d) a hydroxyl group-containing monomer;

wherein, based on a total weight of the conjugated latex particles (A), (a) the conjugated diene monomer or conjugated diene polymer is present in an amount of 10 to 97.4% by weight, (b) the monomer of the group is present in an amount of 1 to 70% by weight, (c) the unsaturated carboxylic acid monomer is present in an amount of 1 to 20% by weight and (d) the hydroxyl group-containing monomer is present in an amount of 0.5 to 5% by weight;
wherein, based on a total weight of the acrylic copolymer latex particles (B), (a) the (meth)acrylic acid ester monomer is present in an amount of 10 to 96.9% by weight, (b) the monomer of the group is present in an amount of 1 to 60% by weight, (c) the unsaturated carboxylic acid monomer is present in an amount of 1 to 10% by weight, and (d) the hydroxyl group-containing monomer is present in an amount of 1 to 10% by weight;
wherein the conjugated diene latex particles (A) has a pH of 3 to 6.5;
wherein the acrylic copolymer latex particles (B) has a pH of 3 to 6.5;
wherein the composite latex has a pH of 3 to 6.5; and
wherein the conjugated diene latex particles (A) and the copolymer latex particles (B) are present in the composite latex in a weight ratio of 20:80 to 40:60.

2. The binder composition according to claim 1 , wherein the conjugated diene monomer is selected from the group consisting of 1,3-butadiene, isoprene, chloroprene and piperidine, and the conjugated diene polymer is a polymer of two or more monomers selected from the group consisting of 1,3-butadiene, isoprene, chloroprene and piperidine, a styrene-butadiene copolymer, an acrylonitrile-butadiene copolymer, a styrene-isoprene copolymer, an acrylate-butadiene rubber, an acrylonitrile-butadiene-styrene rubber, an ethylene-propylene-diene-based polymer, a partially hydrogenated, epoxidized or brominated form of these polymers, and a mixture thereof.

3. The binder composition according to claim 1 , wherein the (meth)acrylic acid ester monomer comprises one or more monomers selected from the group consisting of methylacrylate, ethylacrylate, propylacrylate, isopropylacrylate, n-butylacrylate, isobutylacrylate, n-amylacrylate, isoamylacrylate, n-ethylhexylacrylate, 2-ethylhexylacrylate, methylmethacrylate, ethylmethacrylate, propylmethacrylate, isopropylmethacrylate, n-butylmethacrylate, isobutylmethacrylate, n-amyl methacrylate, isoamylmethacrylate, n-hexylmethacrylate, n-ethylhexyl methacrylate, 2-ethylhexyl methacrylate lauryl acrylate, ceryl acrylate, stearyl acrylate, lauryl methacrylate, cetyl methacrylate, and stearyl methacrylate.

4. The binder composition according to claim 1 , wherein the acrylate monomer comprises one or more monomers selected from the group consisting of methacryloxy ethylethyleneurea, β-carboxy ethylacrylate, aliphatic monoacrylate, dipropylene diacrylate, ditrimethylopropane tetraacrylate, dipentaerythritol hexaacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and glycidyl methacrylate.

5. The binder composition according to claim 1 , wherein the vinyl monomer comprises one or more monomers selected from the group consisting of styrene, α-methylstyrene, β-methylstyrene, p-t-butylstyrene and divinylbenzene.

6. The binder composition according to claim 1 , wherein the (meth)acrylamide monomer comprises one or more monomers selected from the group consisting of acrylamide, n-methylol acrylamide, n-butoxy methacrylamide, methacrylamide, n-methylol methacrylamide, and n-butoxy methylmethacrylamide.

7. The binder composition according to claim 1 , wherein the nitrile monomer is alkenyl cyanide.

8. The binder composition according to claim 7 , wherein the alkenyl cyanide comprises one or more monomers selected from the group consisting of acrylonitrile, methacrylonitrile and allyl cyanide.

9. The binder composition according to claim 1 , wherein the unsaturated carboxylic acid monomer comprises one or more monomers selected from the group consisting of maleic acid, fumaric acid, methacrylic acid, acrylic acid, glutaric acid, itaconic acid, tetrahydrophthalic acid, crotonic acid, isocrotonic acid and nadic acid.

10. The binder composition according to claim 1 , wherein the hydroxyl group-containing monomer comprises one or more monomers selected from the group consisting of hydroxyethyl acrylate, hydroxybutyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and hydroxy butyl methacrylate.

11. The binder composition according to claim 1 , wherein the binder composition has a swelling index with respect to an electrolyte of 1.5 to 5.

12. An electrode mix for secondary batteries comprising:
the binder composition according to claim 1 ; and
an electrode active material capable of intercalating and de-intercalating lithium.

13. An electrode for secondary batteries comprising the electrode mix according to claim 12 applied to a current collector.

14. A lithium secondary battery comprising the electrode for secondary batteries according to claim 13 .

Assignees

• Lg Chemical Ltd

Inventors

• Kang Min Ah
• Ryu Dong Jo
• Choi Cheol Hoon
• Han Seon Hee
• Han Hye Soo

Classifications

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M4/131

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M4/622 Primary

  being polymers · CPC title

• C08F212/08

  Styrene · CPC title