Aqueous vinylidene fluoride-(meth)acrylic co-polymer latex, electrode and lithium ion secondary battery using the same

Patent metadata

Field	Value
Publication number	US-10079388-B2
Application number	US-201214232894-A
Country	US
Kind code	B2
Filing date	Jul 13, 2012
Priority date	Jul 15, 2011
Publication date	Sep 18, 2018
Grant date	Sep 18, 2018

Abstract

The present invention pertains to an aqueous composition comprising: (A) an aqueous latex comprising at least one vinylidene fluoride (VDF) polymer [polymer (F)] comprising recurring units derived from vinylidene fluoride (VDF) and at least one (meth)acrylic monomer (MA) having formula (I) here below: wherein: —R 1 , R 2 and R 3 , equal to or different from each other, are independently selected from a hydrogen atom and a C 1 -C 3 hydrocarbon group, and —R OH is a hydrogen atom or a C 1 -C 5 hydrocarbon moiety comprising at least one hydroxyl group, (B) at least one powdery electrode material, and (C) optionally, less than 10% by weight, based on the total weight of the aqueous composition, of at least one organic solvent (S), wherein the polymer (F) in the aqueous latex is under the form of primary particles having an average primary particle size of less than 1 μm, as measured according to ISO 13321. The present invention also pertains to a process for manufacturing an electrode using said aqueous composition, to an electrode comprising a metal substrate coated on at least one surface with said aqueous composition and to use of said electrode for manufacturing a non-aqueous-type electrochemical device.

First claim

The invention claimed is:

1. An aqueous composition comprising:
(A) an aqueous latex comprising at least one polymer (F), wherein the polymer (F) comprises recurring units derived from vinylidene fluoride (VDF) and between 0.01% and 10% by moles of recurring units derived from at least one (meth)acrylic monomer (MA) of formula (I):

wherein:
R 1 , R 2 and R 3 , equal to or different from each other, are independently selected from a hydrogen atom and a C 1 -C 3 hydrocarbon group, and
R OH is a hydrogen atom or a C 1 -C 5 hydrocarbon moiety comprising at least one hydroxyl group,

(B) at least one powdery electrode material, and
(C) optionally, less than 10% by weight, based on the total weight of the aqueous composition, of at least one organic solvent (S),

wherein the polymer (F) in the aqueous latex is in the form of primary particles having an average primary particle size of less than 1 μm, as measured according to ISO 13321.

2. The aqueous composition according to claim 1 , wherein the aqueous latex is prepared by aqueous emulsion polymerization in an aqueous medium of the at least one vinylidene fluoride (VDF) and the at least one (meth)acrylic monomer (MA) having formula (I), optionally in the presence of at least one other comonomer (C).

3. The aqueous composition according to claim 1 , wherein the aqueous latex has the primary particles homogenously dispersed therein.

4. The aqueous composition according to claim 1 , wherein the at least one (meth)acrylic monomer (MA) of formula (I) is at least one (meth)acrylic monomer (MA) of formula (II):

wherein:
R′ 1 , R′ 2 and R′ 3 are hydrogen atoms, and
R′ OH is a hydrogen atom or a C 1 -C 5 hydrocarbon moiety comprising at least one hydroxyl group.

5. The aqueous composition according to claim 1 , wherein the (meth)acrylic monomer (MA) of formula (I) is acrylic acid (AA).

6. The aqueous composition according to claim 1 , consisting of:
(A) the aqueous latex, wherein said aqueous latex consists of:
from 10% to 50% by weight, based on the total weight of the aqueous latex, of the at least one polymer (F), and
optionally, at least one surfactant selected from a fluorinated surfactant (FS), a hydrogenated surfactant (H) and mixtures thereof, and

(B) from 20% to 80% by weight, based on the total weight of the aqueous composition, of the at least one powdery electrode material,

wherein the average primary particle size of the primary particles of the polymer (F) is between 50 nm and 600 nm, as measured according to ISO 13321.

7. The aqueous composition according to claim 1 , wherein the aqueous latex is prepared by an aqueous emulsion polymerization process without any subsequent coagulation step.

8. The aqueous composition according to claim 1 , consisting of:
(A) the aqueous latex, wherein said aqueous latex consists of:
from 20% to 35% by weight, based on the total weight of the aqueous latex, of the at least one polymer (F), and
optionally, at least one surfactant selected from a fluorinated surfactant (FS), a hydrogenated surfactant (H) and mixtures thereof, and

(B) from 40% to 70% by weight, based on the total weight of the aqueous composition, of the at least one powdery electrode material,

wherein the average primary particle size of the primary particles of the polymer (F) is between 80 nm and 400 nm, as measured according to ISO 13321.

9. The aqueous composition according to claim 8 , wherein the at least one (meth)acrylic monomer (MA) of formula (I) is at least one (meth)acrylic monomer (MA) of formula (II):

wherein:
R′ 1 , R′ 2 and R′ 3 are hydrogen atoms, and
R′ OH is a hydrogen atom or a C 1 -C 5 hydrocarbon moiety comprising at least one hydroxyl group.

10. The aqueous composition according to claim 8 , wherein the (meth)acrylic monomer (MA) of formula (I) is acrylic acid (AA).

11. An electrode comprising a metal substrate coated on at least one surface with the aqueous composition according to claim 1 .

12. The electrode according to claim 11 , comprising:
from 1% to 15% by weight, based on the total weight of the electrode, of the at least one polymer (F),
from 80% to 99% by weight, based on the total weight of the electrode, of the at least one powdery electrode material, and
optionally, up to 10% by weight, based on the total weight of the electrode, of one or more additives.

13. The electrode according to claim 11 , comprising:
from 2% to 12% by weight, based on the total weight of the electrode, of the at least one polymer (F),
from 85% to 98% by weight, based on the total weight of the electrode, of the at least one powdery electrode material, and
optionally, up to 5% by weight, based on the total weight of the electrode, of one or more additives.

14. The electrode according to claim 13 , wherein the at least one (meth)acrylic monomer (MA) of formula (I) is at least one (meth)acrylic monomer (MA) of formula (II):

wherein:
R′ 1 , R′ 2 and R′ 3 are hydrogen atoms, and
R′ OH is a hydrogen atom or a C 1 -C 5 hydrocarbon moiety comprising at least one hydroxyl group.

15. A non-aqueous-type electrochemical device comprising the electrode according to claim 11 .

16. A lithium ion secondary battery comprising the electrode according to claim 11 .

17. A process for manufacturing an electrode, said process comprising:
(i) providing an aqueous latex comprising at least one vinylidene fluoride (VDF) polymer (F), said polymer (F) comprising recurring units derived from vinylidene fluoride (VDF) and at least one (meth)acrylic monomer (MA) of formula (I):

wherein:
R 1 , R 2 and R 3 , equal to or different from each other, are independently selected from a hydrogen atom and a C 1 -C 3 hydrocarbon group, and
R OH is a hydrogen atom or a C 1 -C 5 hydrocarbon moiety comprising at least one hydroxyl group;

(ii) admixing said aqueous latex with at least one powdery electrode material, optionally in the presence of one or more additives, to provide an aqueous electrode-forming composition;
(iii) applying said aqueous electrode-forming composition onto at least one surface of a metal substrate to provide at least one electroactive layer adhered to the at least one surface of said metal substrate; and
(iv) drying said electroactive layer to provide said electrode.

18. The process according to claim 17 , wherein the aqueous electrode-forming composition is for manufacturing negative electrodes or anodes, and said composition comprises:
(a′) from 0.5% to 10% by weight, based on the total weight of (a′)+(b′)+(c′), of the at least one polymer (F),
(b′) from 20% to 80% by weight, based on the total weight of (a′)+(b′)+(c′), of the at least one powdery electrode material, and
(c′) optionally, up to 2% by weight, based on the total weight of (a′)+(b′)+(c′), of a thickener.

Assignees

• Stanga Milena
• Pieri Riccardo
• Bertasa Anna Maria
• Kent Bradley Lane
• Brinati Giulio
• Solvay Specialty Polymers It

Inventors

• Stanga Milena
• Pieri Riccardo
• Bertasa Anna Maria
• Kent Bradley Lane
• Brinati Giulio

Classifications

• H01M4/622 Primary

  being polymers · CPC title

• H01M4/0402

  Methods of deposition of the material · CPC title

• H01M4/133

  Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• C09D127/16

  Homopolymers or copolymers of vinylidene fluoride · CPC title

• H01M10/0525

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