Method for the manufacture of electrodes

1 . A composition [composition (C)] comprising:

from 0.5 wt. % to less than 20 wt. % of at least one semi-crystalline partially fluorinated polymer [polymer (F)] comprising recurring units derived from 1,1-difluoroethylene (VDF) and recurring units derived from at least one hydrogenated monomer comprising at least one carboxylic acid end group [monomer (MA)];

from 10 wt. % to less than 60 wt. % of at least one liquid medium [medium (L)] characterized by a boiling point equal to or higher than 150°° C., wherein said medium (L) is selected from the group consisting of organic carbonates, ionic liquids (IL), or combinations thereof; and

at least 50 wt. % of at least one electro-active compound [compound (EA)];

wherein the above amounts are based on the total weight of said composition (C), and wherein said polymer (F) is characterized by an intrinsic viscosity higher than 0.05 L/g, the intrinsic viscosity being measured from the dropping time of a solution of said polymer (F) at 25° C. at a concentration of 0.2 g/dl in N.N-dimethylformamide using a Ubbelhode viscosimeter, and

wherein the composition (C) is free from any polar solvent [solvent(S)].

2 . The composition (C) according to claim 1 , wherein said polymer (F) comprises recurring units derived from 1,1-difluoroethylene (VDF), recurring units derived from at least one hydrogenated monomer comprising at least one carboxylic acid end group [monomer (MA)], and recurring units derived from at least one partially or fully fluorinated monomer [monomer (F FH )], said monomer (F FH ) being different from VDF.

3 . The composition (C) according to claim 2 , wherein:

said monomer (MA) complies with the following chemical 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;

and said monomer (F FH ) is selected from the group comprising:

—C 2 -C 8 perfluoroolefins;

—C 2 -C 8 hydrogenated fluoroolefins different from VDF;

—CH 2 ═CH—R f0 , wherein R f0 is a C 1 -C 6 perfluoroalkyl;

chloro- and/or bromo- and/or iodo-C 2 -C 6 fluoroolefins;

—CF 2 ═CFOX 0 , wherein X 0 is a C 1 -C 6 fluoro-or perfluoroalkyl; a C 1 -C 12 alkyl group, a C 1 -C 12 oxyalkyl group or a C 1 -C 12 (per) fluorooxyalkyl group having one or more ether groups; group -CF 2 OR f2 wherein R f2 is a C 1 -C 6 fluoro-or perfluoroalkyl group or a C 1 -C 6 (per) fluorooxylalkyl group having one or more ether groups;

—CF 2═ CFOY 0 ,

wherein Y 0 is a C 1 -C 12 alkyl group or (per) fluoroalkyl group, a C 1 -C 12 oxyalkyl group or a C 1 - C 12 (per) fluorooxyalkyl group having one or more ether groups, or a carboxylic or sulfonic acid group, in its acid, acid halide or salt form; or

fluorodioxoles.

4 . The composition (C) according to claim 1 , wherein said polymer (F) comprises:

recurring units derived from VDF and recurring units derived from at least one monomer (MA) [polymer (F*)]; or

recurring units derived from VDF, recurring units derived from at least one monomer (MA), and recurring units derived from at least one monomer (F FH ) [polymer (F**).

5 . The composition (C) according to claim 4 , wherein:

said polymer (F*) comprises:

at least 90% by moles of recurring units derived from VDF,

from 0.05% to 10% by moles of recurring units derived from at least one monomer (MA); and

said polymer (F**) comprises:

at least 80% by moles of recurring units derived from VDF,

from 0.01% to 10% by moles of recurring units derived from at least one monomer (MA), and

from 0.1% to 15% by moles of at least one monomer (F FH ).

6 . The composition (C) according to claim 1 , wherein said composition (C) comprises a conductive compound [compound (C)].

7 . The composition (C) according to claim 6 , wherein said compound (C) is present in said composition (C) in an amount from 0.1 wt. % to 15 wt. % based on the total weight of said composition (C).

8 . The composition (C) according to claim 1 , wherein said composition (C) comprises a polymer [polymer (P)] comprising a backbone complying with the following formula:

—[(CH 2 ) x -CHR 1 -R 2]—

wherein

x is an integer from 1 to 3,

R 1 is a hydrogen or methyl group; and

R 2 is an oxygen atom or a group of formula —OC(═O)R 3, with R 3 being a hydrogen atom or a methyl group, and

wherein said polymer (P) has a melting point (Tm) higher than 25° C. and lower than 120° C.

9 . The composition (C) according to claim 8 , wherein said polymer (P) is present in said composition (C) in an amount higher than 0.1 wt. % and lower than 20 wt. %, based on the total weight of said composition (C).

10 . The composition (C) according to claim 1 , said composition (C) comprising:

from 18 to 40.5 wt. % of said medium (L), optionally comprising at least one salt (M);

from 2 to 14 wt. % of said polymer (F);

from 52 to 82 wt. % of said compound (EA);

from 0.5 to 10 wt. % of a conductive compound [compound (C)]; and

optionally, from 3 to 5 wt. % of a polymer [polymer (P)] comprising a backbone complying with the following formula:

—[(CH 2 ) x -CHR 1 -R 2 ]—

wherein

x is an integer from 1 to 3,

R 1 is a hydrogen or methyl group; and

R 2 is an oxygen atom or a group of formula —OC(═O)R 3 , with R 3 being a hydrogen atom or methyl group, and

wherein said polymer (P) has a melting point (Tm) higher than 25° C. and lower than 120° C.

11 . The composition (C) according to claim 1 , said composition (C) comprising:

from 10 to 40 wt. % of said medium (L), said medium (L) comprising at least one organic carbonate as the only medium (L);

from 2 to 14 wt. % of polymer (F**-1), wherein polymer (F**-1) comprises:

at least 80% by moles of recurring units derived from VDF,

from 0.01% to 10% by moles of recurring units derived from at least one monomer (MA), and

from 5% to 12% by moles of at least one monomer (FFH);

from 52 to 82 wt. % of said compound (EA);

from 0.5 to 10 wt. % of a conductive compound [compound (C)]; and

optionally, from 3 to 5 wt. % of a polymer [polymer (P)] comprising a backbone complying with the following formula:

—[(CH 2 ) x -CHR 1 -R 2 ]—

wherein

x is an integer from 1 to 3,

R 1 is a hydrogen or methyl group; and

R 2 is an oxygen atom or a group of formula —OC(═O)R 3, with R 3 being a hydrogen atom or methyl group, and

wherein said polymer (P) has a melting point (Tm) higher than 25° C. and lower than 120° C.

12 . A process for the manufacture of an assembly, said process comprising:

(a) providing a substrate;

(b) providing composition (C) as defined in claim 11 in the form of pellets;

(c) heating said composition (C) at a temperature higher than 100° C.;

(d) extruding the composition (C) provided in step (b) onto the substrate provided in step (a), thereby providing an assembly comprising a substrate coated with at least one layer consisting of said composition (C).

13 . An assembly comprising:

at least one substrate, and

directly adhered onto said substrate, at least one layer [layer (L1)] consisting of composition (C) of claim 1 ,

wherein said assembly is a positive electrode or a negative electrode.

14 . A secondary battery comprising:

a positive electrode,

a negative electrode, and

a membrane interposed between said positive electrode and said negative electrode, wherein at least one of said positive electrode and said negative electrode is the assembly according to claim 13 .

15 . A process for the manufacture of an assembly, said process comprising:

(i) providing a substrate;

(ii) providing composition (C) comprising:

from 0.5 wt. % to less than 20 wt. % of at least one semi-crystalline partially fluorinated polymer [polymer (F)] comprising recurring units derived from 1,1-difluoroethylene (VDF);

from 10 wt. % to less than 60 wt. % of at least one liquid medium [medium (L)] characterized by a boiling point equal to or higher than 150° C., wherein said medium (L) is selected from the group consisting of organic carbonates, ionic liquids (IL), or combinations;

at least 50 wt. % of at least one electro-active compound [compound (EA)];

wherein the above amounts are based on the total weight of said composition (C), and

wherein said polymer (F) is characterized by an intrinsic viscosity higher than 0.05 L/g, the intrinsic viscosity being measured from the dropping time of a solution of said polymer (F) at 25° C. at a concentration of 0.2 g/dL in N.N-dimethylformamide using a Ubbelhode viscosimeter; and

wherein the composition (C) is free from any polar solvent [solvent(S)];

(iii) heating said composition (C) at a temperature higher than 100° C.;

(iv) extruding the composition (C) provided in step (ii) onto the substrate provided in step (i), thereby providing an assembly comprising a substrate coated with at least one layer consisting of said composition (C).