Electroactive ionic liquids and surface-modified substrates containing them
The present invention relates an electro-active polymeric ionic liquid including imidazolium-based molecules, said imidazolium-based molecule comprising each at least: —one imidazolium moiety associated with a negatively-charged counter-ion, and —one reducible group selected from: Formula (IV), —an anthraquinone derivative of formula (IV): with R 1 representing a hydrogen atom or a C 1 -C 6 -alkyl group, —a viologen group, and —a metallocene reducible group such as a cobaltocene group.
1. An electro-active polymeric ionic liquid comprising imidazolium-based repeated units, each of said imidazolium-based repeated units comprising at least:
an imidazolium moiety associated with a negatively charged counter-ion,
a metallocene oxidizable group and/or a reducible group,
the reducible group being selected from:
an anthraquinone derivative of formula (IV):
with R 1 representing a hydrogen atom or a C 1 -C 6 -alkyl group,
a viologen group of formula (V):
with R′ 2 representing a hydrogen atom, a C 1 -C 8 alkyl group or a C 2 -C 6 alkenyl group,
X and X′ identical or different, and each independently representing a halogen group, or
a metallocene reducible group.
2. The electro-active polymeric ionic liquid according to claim 1 , wherein the polymeric ionic liquid presents:
imidazolium-based repeated units, each of said imidazolium-based repeated units comprising at least:
an imidazolium moiety associated with a negatively charged counter-ion, and
a metallocene oxidizable group and
imidazolium-based repeated units, each of said imidazolium-based repeated units comprising at least:
an imidazolium moiety associated with a negatively charged counter-ion, and
a reducible group, the reducible group being selected from an anthraquinone derivative, a viologen group, or a metallocene reducible group.
3. The electro-active polymeric ionic liquid according to claim 1 , wherein the imidazolium-based repeated units comprise:
an imidazolium moiety associated with a negatively charged counter ion, and
a metallocene oxidizable group, and
a reducible group selected from anthraquinone derivative, a viologen group, or a metallocene reducible group.
4. Electro-active polymeric ionic liquid of claim 1 , wherein the polymeric ionic liquid is polymerized from an imidazolium-based molecule of formula (I):
wherein
m is 0 or 1;
n is equal to 0 or 1;
L 1 is selected from: a bond, a C 1 -C 6 alkyl group where one or two carbon atoms are optionally replaced by an oxygen atom, a CO—(C1-C6)alkyl group, a (C1-C6)alkyl-CO— group, a CONH—(C 1 -C 6 )alkyl group, a (C 1 -C 6 )alkyl-CONH— group, a COO—(C 1 -C 6 )alkyl group, and a (C 1 -C 6 )alkyl-COO— group;
A and B are different and are selected from:
an imidazolium group of formula (IIa):
Z − being a negatively charged counter ion,
a metallocene oxidizable group of formula (III)
M being a transition metal ion, or
a reducible group selected from:
an anthraquinone derivative of formula (IV):
with R 1 representing a hydrogen atom or a C 1 -C 6 -alkyl group, or
a metallocene reducible group, or
a viologen group of formula (V):
with R′2 representing a hydrogen atom, a C 1 -C 8 alkyl group or a C 2 -C 6 alkenyl group, and X and X′ identical or different, and each independently representing a halogen group,
provided that at least A or B is an imidazolium group of formula (IIa),
when n is 1, then
C is selected from:
a metallocene oxidizable group of formula (III) as defined above, or
a reducible group as defined above,
provided that A, B and C are different;
L 2 is selected from a bond, a C 1 -C 6 alkyl group, a CONH—(C 1 -C 6 )alkyl group, a (C 1 -C 6 )alkyl-CONH— group, a COO—(C 1 -C 6 )alkyl group, and a (C 1 -C 6 )alkyl-COO— group,
wherein one or two carbon atoms in the (C 1 -C 6 )-alkyl group are optionally replaced by an oxygen atom, a CO—(C 1 -C 6 )alkyl group, a (C 1 -C 6 )alkyl-CO— group,
when n is 0, then
A and B are different and are selected from an imidazolium group of formula (IIa) as defined above, and a reducible group as defined above
L 2 is a C 1 -C 6 alkyl group if B is an imidazolium group of formula (IIa)
when m is 1 then
A or B is an imidazolium group of formula (IIa),
A is not a viologen group of formula (V) as defined above,
L 3 is selected from a bond, a C 1 -C 6 alkyl group, a CONH—(C 1 -C 6 )alkyl group, a (C 1 -C 6 )alkyl-CONH— group, a COO—(C 1 -C 6 )alkyl group, and a (C 1 -C 6 )alkyl-COO— group,
wherein one or two carbon atoms in the (C 1 -C 6 )-alkyl group are optionally replaced by an oxygen atom, and
R is a hydrogen atom, a C 1 -C 6 alkyl group or a C 5 -C 10 -aryl group;
when m is 0 then
L 3 is a hydrogen atom if A is metallocene oxidizable group of formula (III) or a reducible group,
L 3 is a C 1 -C 6 alkyl group if A is an imidazolium group of formula (IIa), and
one of A and C is a viologen group of formula (V) as defined above with R′ 2 representing a C 2 -C 6 alkenyl group.
5. The electro-active polymeric ionic liquid of claim 1 , wherein the reducible group is an anthraquinone derivative of formula (IV) with R 1 representing a hydrogen atom.
6. The electro-active polymeric ionic liquid of claim 1 , wherein the metallocene oxidizable group is a ferrocene group.
7. The electro-active polymeric ionic liquid of claim 1 , wherein the negatively charged counter-ion is PF 6 − , BF 4 − , Cl − , Br − or bis(trifluoromethanesulfonyl)imidate CF 3 SO 2 NSO 2 CF 3 − .
8. The electro-active polymeric ionic liquid of claim 1 , wherein said imidazolium-based molecule is selected from:
with Z − , Z 1 − , X − and X′ − as defined in claim 4 .
9. The electro-active polymeric ionic liquid of claim 1 , wherein said imidazolium-based molecule is:
with Z − being a negatively charged counter ion, X − and X′ − being identical or different, and each independently representing a halogen group.
10. Surface-modified substrate with an immobilized electro-active polymeric ionic liquid as defined in claim 1 .
11. The surface-modified substrate of claim 10 , wherein the substrate is a current collector of an electrode.
12. The surface-modified substrate of claim 10 , wherein on the substrate is immobilized:
a combination of:
1) an electro-active polymeric ionic liquid comprising imidazolium-based repeated units comprising at least one imidazolium moiety, one negatively charged counter-ion and one metallocene oxidizable group, and
2) an electro-active polymeric ionic liquid comprising imidazolium-based repeated units comprising at least one imidazolium moiety, one negatively charged and one reducible group,
or
an electro-active polymeric ionic liquid comprising imidazolium-based repeated units comprising at least: 1) one imidazolium moiety associated with one negatively charged counter-ion, 2) one metallocene oxidizable group and 3) one reducible group.
13. An energy storage device comprising at least two surface-modified electrodes comprising a surface-modified substrate with an immobilized electro-active polymeric ionic liquid as defined in claim 1 , wherein the substrate is a current collector of an electrode, and wherein the two surface-modified electrodes are different, and
the first electrode comprises a electro-active polymeric ionic liquid with imidazolium-based repeated units comprising at least:
one imidazolium moiety associated with one negatively charged counter-ion, and
one metallocene oxidizable group;
and the second electrode comprises an electro-active polymeric ionic liquid with imidazolium-based repeated units comprising at least:
one imidazolium moiety associated with one negatively charged counter-ion, and
one reducible group as defined in claim 1 .
14. An energy storage device comprising at least two surface-modified electrodes comprising a surface-modified substrate with an immobilized electro-active polymeric ionic liquid as defined in claim 1 , wherein the substrate is a current collector of an electrode, and wherein the two surface-modified electrodes are identical, and the first and second electrode comprise a electro-active polymeric ionic liquid with imidazolium-based repeated units comprising at least:
one imidazolium moiety associated with one negatively charged counter-ion,
one metallocene oxidizable group, and
one reducible group as defined in claim 1 .
15. The energy storage device according to claim 14 , wherein the surface of the surface-modified electrode is as follows:
16. The energy storage device according to claim 15 , wherein the surface-modified electrodes are planar, interdigitated and membraneless.