Granted Patent B2

US 12,612,515 · App. 18/042,119 · Granted Apr 28, 2026

Inventors: Takuya Nakayama (Minato-ku, JP); Kana Masuda (Minato-ku, JP); Sadatoshi Heiguchi (Minato-ku, JP); Yingcheng Lin (Minato-ku, JP)

Assignee: ENEOS Materials Corporation

C08L55/02C08L25/04H01M4/0404H01M4/386H01M4/622C08L2203/20

Abstract

Claims (28)

1 . A binder composition for an electrical storage device, comprising:

a polymer (A); and

a liquid medium (B),

wherein, with respect to 100 mass % in total of repeating units contained in the polymer (A), the polymer (A) contains:

15 mass % to 60 mass % of a repeating unit (a1) derived from a conjugated diene compound; and

1 mass % to 10 mass % of a repeating unit (a2) derived from an unsaturated carboxylic acid,

wherein tan δ (loss elastic modulus/storage elastic modulus) in dynamic viscoelasticity of the polymer (A) has one peak top in a range of from −40° C. or more to less than 50° C., and has one peak top in a range of from 50° C. or more to 150° C. or less, and

wherein, when the tan δ at the peak top in the range of from −40° C. or more to less than 50° C. is represented by tan δ(Tp1), and the tan δ at the peak top in the range of from 50° C. or more to 150° C. or less is represented by tan δ(Tp2), a relationship of the following expression (1) is satisfied,

tan δ( Tp 2)/tan δ( Tp 1)≥0.5  (1).

2 . The binder composition for an electrical storage device according to claim 1 ,

wherein the polymer (A) further contains 35 mass % to 75 mass % of a repeating unit (a3) derived from an aromatic vinyl compound, and

wherein a total amount of the repeating unit (a1), the repeating unit (a2), and the repeating unit (a3) is 80 mass % or more.

3 . The binder composition for an electrical storage device according to claim 1 ,

wherein the polymer (A) contains at least one of a repeating unit (a4) derived from an unsaturated carboxylic acid ester or a repeating unit (a5) derived from an α,β-unsaturated nitrile compound, and

wherein a total amount of the repeating unit (a1), the repeating unit (a2), the repeating unit (a4), and the repeating unit (a5) is 65 mass % or more.

4 . The binder composition for an electrical storage device according to claim 1 , wherein the polymer (A) has a Martens hardness of 15 MPa or more, which is calculated using a picoindenter.

5 . The binder composition for an electrical storage device according to claim 1 ,

wherein the polymer (A) is polymer particles, and

wherein the polymer particles have a number average particle diameter of 50 nm or more and 500 nm or less.

6 . The binder composition for an electrical storage device according to claim 1 , wherein the liquid medium (B) is water.

7 . A slurry for an electrical storage device electrode, comprising:

the binder composition for an electrical storage device of claim 1 ; and

an active material.

8 . The slurry for an electrical storage device electrode according to claim 7 , wherein the active material is a silicon material.

9 . An electrical storage device electrode, comprising:

a current collector; and

an active material layer formed on a surface of the current collector by applying and drying the slurry for an electrical storage device electrode of claim 7 .

10 . An electrical storage device, comprising the electrical storage device electrode of claim 9 .

Assignments (2)

Priority Claims (1)

Continuity (1)

References Cited (66)