Binder composition for non-aqueous secondary battery functional layer, slurry composition for non-aqueous secondary battery functional layer, non-aqueous secondary battery member, and non-aqueous secondary battery

Patent metadata

Field	Value
Publication number	US-11831019-B2
Application number	US-201917040980-A
Country	US
Kind code	B2
Filing date	Apr 2, 2019
Priority date	Apr 3, 2018
Publication date	Nov 28, 2023
Grant date	Nov 28, 2023

Abstract

Provided is a binder composition capable of forming a functional layer that can both inhibit post-cycling swelling of a secondary battery and increase charge carrier acceptance of the secondary battery at low temperatures. The binder composition contains a first polymer, a second polymer, and a solvent. The first polymer is a block copolymer including a block region formed of an aromatic vinyl monomer unit and a block region formed of an aliphatic conjugated diene monomer unit and/or a hydrogenated aliphatic conjugated diene monomer unit. The second polymer is a random copolymer including a 1,3-pentadiene unit and/or a hydrogenated 1,3-pentadiene unit.

First claim

The invention claimed is:

1. A binder composition for a non-aqueous secondary battery functional layer, comprising a first polymer, a second polymer, and a solvent, wherein
the first polymer is a block copolymer including a block region formed of an aromatic vinyl monomer unit and a block region formed of either or both of an aliphatic conjugated diene monomer unit and a hydrogenated aliphatic conjugated diene monomer unit,
the second polymer is a random copolymer including either or both of a 1,3-pentadiene unit and a hydrogenated 1,3-pentadiene unit,
the second polymer further includes an alicyclic monoolefin monomer unit having a carbon number of not less than 4 and not more than 6, and a proportion constituted by the alicyclic monoolefin monomer unit having the carbon number of not less than 4 and not more than 6 in the second polymer is 10 mass % or more and 35 mass % or less, and
content of the second polymer is not less than 0.1 mass % and 8.0 mass % or less of total content of the first polymer and the second polymer, and
wherein the second polymer further includes an acyclic monoolefin monomer unit having a carbon number of not less than 4 and not more than 8, and a proportion constituted by the acyclic monoolefin monomer unit having the carbon number of not less than 4 and not more than 8 in the second polymer is 5 mass % or more and 30 mass % or less.

2. The binder composition for a non-aqueous secondary battery functional layer according to claim 1 , wherein proportional content of the aromatic vinyl monomer unit in the first polymer is not less than 10 mass % and not more than 50 mass %.

3. The binder composition for a non-aqueous secondary battery functional layer according to claim 1 , wherein a total of proportional content of the 1,3-pentadiene unit and proportional content of the hydrogenated 1,3-pentadiene unit in the second polymer is not less than 20 mass % and not more than 70 mass %.

4. The binder composition for a non-aqueous secondary battery functional layer according to claim 1 , wherein the second polymer has a softening point of not lower than 70° C. and not higher than 170° C.

5. The binder composition for a non-aqueous secondary battery functional layer according to claim 1 , wherein the second polymer has an acid value of not less than 1 KOH-mg/g and not more than 20 KOH-mg/g.

6. The binder composition for a non-aqueous secondary battery functional layer according to claim 1 , wherein the aliphatic conjugated diene monomer unit is an isoprene unit, and the hydrogenated aliphatic conjugated diene monomer unit is a hydrogenated isoprene unit.

7. The binder composition for a non-aqueous secondary battery functional layer according to claim 1 , wherein a coupling ratio of the first polymer is 60 mass % or more and 92 mass % or less, and the coupling ratio is a mass proportion constituted by coupling moiety-containing structures among all structures of the first polymer.

8. A slurry composition for a non-aqueous secondary battery functional layer comprising the binder composition for a non-aqueous secondary battery functional layer according to claim 1 .

9. The slurry composition for a non-aqueous secondary battery functional layer according to claim 8 , further comprising electrode active material particles.

10. The slurry composition for a non-aqueous secondary battery functional layer according to claim 8 , further comprising non-conductive particles.

11. A non-aqueous secondary battery member comprising a functional layer for a non-aqueous secondary battery formed using the slurry composition for a non-aqueous secondary battery functional layer according to claim 8 .

12. A non-aqueous secondary battery comprising the non-aqueous secondary battery member according to claim 11 .

Assignees

• Zeon Corp

Inventors

• Ishii Hidetake
• Yamamoto Norikazu

Classifications

• H01M4/622 Primary

  being polymers · CPC title

• C08L53/02

  of vinyl-aromatic monomers and conjugated dienes · CPC title

• H01M4/13

  Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof · CPC title

• H01M10/0525

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

• H01M50/443

  Particulate material · CPC title