Binder for rechargeable lithium battery, negative electrode plate including the same, and rechargeable lithium battery including the same

Patent metadata

Field	Value
Publication number	US-2026031358-A1
Application number	US-202519269742-A
Country	US
Kind code	A1
Filing date	Jul 15, 2025
Priority date	Jul 24, 2024
Publication date	Jan 29, 2026
Grant date	—

Abstract

Examples of this disclosure include binders, negative electrode plates, and rechargeable lithium batteries. The binder includes a core including a first polymer having a glass transition temperature that is equal to or less than about 15° C., and a shell on the core and including a second polymer having a glass transition temperature that is equal to or greater than about 180° C. An amount of the shell is less than the amount of the core.

First claim

What is claimed is:

1 . A binder for a rechargeable lithium battery, the binder comprising:
a core including a first polymer having a glass transition temperature that is equal to or less than about 15° C.; and a shell on the core and including a second polymer having a glass transition temperature that is equal to or greater than about 180° C., wherein an amount of the shell is less than an amount of the core.

2 . The binder of claim 1 , wherein the amount of the shell is about 3 wt % to about 15 wt % relative to a total weight of the binder.

3 . The binder of claim 1 , wherein the first polymer includes at least one of:
a first unit derived from an aromatic vinyl-based monomer; a second unit derived from a (meth)acrylate-based monomer; a third unit derived from a (meth)acrylic acid-based monomer; and a fourth unit derived from a (meth)acrylamide-based monomer.

4 . The binder of claim 1 , wherein the glass transition temperature of the first polymer is in a range of about −20° C. to about 15° C.

5 . The binder of claim 1 , wherein a ductility of the first polymer is greater than a ductility of the second polymer.

6 . The binder of claim 1 , wherein the second polymer includes:
a fifth unit derived from an acrylic acid-based monomer; a sixth unit derived from an acrylonitrile-based monomer; and a seventh unit derived from a sulfonic acid-based monomer.

7 . The binder of claim 6 , wherein the sulfonic acid-based monomer includes at least one of 2-acrylamido-2-methylpropane sulfonic acid, sodium styrene sulfonate, and sodium sulfopropyl (meth)acrylate.

8 . The binder of claim 6 , wherein an amount of the seventh unit derived from the sulfonic acid-based monomer in the second polymer is in a range of about 1 wt % to about 40 wt % relative to a total weight of the second polymer.

9 . The binder of claim 6 , further comprising an eighth unit derived from a water-soluble monomer,
wherein the water-soluble monomer includes at least one of (meth)acrylamide, N-isopropylacrylamide, N-(2-hydroxyethyl)acrylamide, N-(2-hydroxyethyl)methacrylamide, 2-hydroxyethyl (meth)acrylate, vinylpyrrolidone, vinylacetamide, vinylformamide, and vinyl alcohol.

10 . The binder of claim 1 , wherein an average molecular weight of the second polymer is in a range of about 300,000 to about 2,000,000.

11 . The binder of claim 1 , wherein the glass transition temperature of the second polymer is in a range of about 180° C. to about 240° C.

12 . The binder of claim 1 , wherein a rigidity of the second polymer is greater than a rigidity of the first polymer.

13 . The binder of claim 1 , wherein the shell is more hydrophilic than the core.

14 . The binder of claim 1 , wherein an average particle diameter of the binder is in a range of about 250 nm to about 1,500 nm.

15 . A negative electrode plate, comprising:
a negative electrode current collector; and a negative electrode active material layer, wherein the negative electrode active material layer includes:
a negative electrode active material; and
the binder for the rechargeable lithium battery as set forth in claim 1 .

16 . The negative electrode plate of claim 15 , wherein an adhesive force between the negative electrode current collector and the negative electrode active material layer is in a range of about 1.2 gf/mm to about 1.8 gf/mm.

17 . A rechargeable lithium battery including the binder for the rechargeable lithium battery as set forth in claim 1 .

18 . The rechargeable lithium battery of claim 17 , wherein an electrode plate at a full charge of the rechargeable lithium battery has a delamination rate that is equal to or less than about 10%.

19 . The rechargeable lithium battery of claim 17 , wherein a resistance of the rechargeable lithium battery is less than about 92.0 mΩ.

20 . The rechargeable lithium battery of claim 17 , wherein a cycle-life retention rate of the rechargeable lithium battery is equal to or greater than about 85%.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Cho Yunshik
• Lee Kukjoo
• Park Sujin
• Lee Hyunseop
• Jung Kyunghwa
• Han Imkyung
• Choi Jewon
• Kim Eunji
• Cho Minho
• Kim Hana
• Choi Kyubuem

Classifications

• C08L2207/53

  Core-shell polymer · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• C08L35/02

  Homopolymers or copolymers of esters (C08L35/06, C08L35/08 take precedence) · CPC title

• C08L33/08

  Homopolymers or copolymers of acrylic acid esters · CPC title

• C08L25/14

  with unsaturated esters · CPC title