Polymers comprising imidazole derivatives and their use in electrochemical cells

1. An element of an electrochemical cell comprising a polymer, wherein said polymer:

(i) comprises monomeric units derived from Formulae I and II:

(ii) is a random or a block copolymer of Formula IV:

(iii) is a random or a block copolymer of Formula V:

(iv) comprises monomeric units derived from Formula I:

or

(v) is a homopolymer of Formula III:

wherein,

R 1 and R 2 are each independently selected from H, CN, F, and optionally fluorinated C 1-6 alkyl groups, wherein at least one R 1 and R 2 is CN;

R 3 is a hydrogen atom or an optionally substituted C 1-6 alkyl group;

R 4 , R 6 , and R 7 are each independently selected from a hydrogen atom and optionally substituted C 1-6 alkyl groups; and

R 5 is selected from —CO 2 H, optionally substituted —CO 2 C 1-6 alkyl groups, —C(O)NH 2 , optionally substituted —OC 1-6 alkyl groups, optionally substituted C 6 aryl groups, optionally substituted C 5-6 heteroaryl groups, —CN, —SO 3 H, —SO 2 NH 2 , and optionally substituted —SO 3 C 1-6 alkyl groups;

or

R 5 taken together with R 7 and their adjacent carbon atoms form a 5 or 6-membered heterocycle;

L 1 and L 2 are independently selected from H, an alkyl group, a residue of a polymerisation initiator, and a linker between two or more of the polymer chains;

L 3 is selected from linear or branched alkyl groups and linkers between polymer chains;

n 1 is an integer selected such that the average molecular weight is from about 2,000 to about 50,000 g/mol;

n 2 and n 3 are integers representing the number of each monomeric unit within the polymer and wherein, in Formula IV, n 2 and n 3 are selected such that the average molecular weight is from about 2,000 to about 50,000 g/mol; and the ratio n 2 :n 3 range from 9:1 to 1:1; and

n 4 and n 5 are each selected from 1 to 4, wherein, in Formula V, n 2 , n 3 , n 4 and n 5 are selected such that the number average molecular weight is from about 2 000 to about 50 000 g/mol, or from about 3 000 to about 10 000 g/mol, and the ratio (n 2 ×n 4 ):(n 3 ×n 5 ) range from 9:1 to 1:1;

or a salt thereof.

2. The element of claim 1 , wherein R 1 is CN and R 2 is an optionally fluorinated C 1-6 alkyl group, or R 2 is CN and R 1 is an optionally fluorinated C 1-6 alkyl group, or both R 1 and R 2 are CN.

3. The element of claim 1 , wherein R 3 is H.

4. The element of claim 1 , wherein R 3 is an optionally substituted C 1-6 alkyl group.

5. The element of claim 1 , wherein at least one of R 4 , R 6 , and R 7 is H.

6. The element of claim 1 , wherein R 4 is an optionally substituted C 1-6 alkyl group.

7. The element of claim 1 , wherein R 5 is CO 2 H, or an optionally substituted —CO 2 C 1-6 alkyl group.

8. The element of claim 1 , wherein R 5 is an optionally substituted —OC 1-6 alkyl group.

9. The element of claim 1 , wherein R 5 taken together with R 7 and their adjacent carbon atoms form a 5-membered heterocycle.

10. The element of claim 1 , wherein the polymer in (i) to (iii) comprises between 10 mol % and 90 mol % or between 10 mol % and 60 mol % or between 15 mol % and 40 mol % of monomeric units derived from a vinylimidazole derivative of Formula I, each upper and lower values being included.

11. The element of claim 1 , wherein the polymer is of Formula IV and the ratio n 2 :n 3 ranges from 4:1 to 3:2, or is of about 7:3.

12. The element of claim 1 , wherein the polymer is of Formula V and the ratio (n 2 ×n 4 ):(n 3 ×n 5 ) ranges from 4:1 to 3:2, or is of about 7:3, and/or wherein n 4 +n 5 =3 or 4.

13. The element of claim 1 , wherein the polymer is of Formula V and L 3 is selected from branched alkyl groups and functionalized branched alkyl groups.

14. The element of claim 1 , wherein said polymer is as defined in (i) to (iii) and is a random copolymer.

15. The element of claim 1 , wherein said polymer is as defined in (i) to (iii) and is a block copolymer.

16. The element of claim 1 , wherein said polymer is as defined in (i) to (iii) and is a branched or hyperbranched copolymer including comb and dendritic, or is a star copolymer wherein linear chains of said star copolymer are homogeneous or heterogenous in length and structure.

17. The element of claim 1 , wherein said linkers L 1 and L 2 are selected from a group consisting of linear or branched alkyl, alkoxyl, and aryl groups, each of which may be further substituted.

18. The element of claim 1 , wherein said linkers L 1 and L 2 groups optionally comprise two or more functional groups comprising heteroatoms selected from oxygen, nitrogen and sulfur.

19. The element of claim 1 , wherein the said salts of the polymers are selected from alkali, and alkaline earth metal salts.

20. The element of claim 1 , wherein said element is an electrode material, an electrolyte composition and/or a separator.

21. An electrode material, the electrode material being an element as defined in claim 1 comprising the polymer and an electrochemically active material.

22. The electrode material of claim 21 , wherein said polymer is a binder.

23. The electrode material of claim 22 , wherein said binder further comprises a second polymer selected from polymers based on glycidyl, acrylic or methacrylic acid, vinyl alkyl ether, thiol-containing monomers, fluorine containing polymers, water soluble binders, styrene butadiene rubber, butadiene acrylonitrile rubber, hydrogenated butadiene acrylonitrile rubber, epichlorohydrin rubber, acrylate rubber, cellulose-based binders, ion-conductive polymer binders and any combination of two or more of these.

24. The electrode material of claim 21 , wherein said electrode material comprises particles having a core-shell structure, wherein the shell comprises a shell composition comprising the polymer and the core comprises the electrochemically active material.

25. An electrolyte, the electrolyte being an element as defined in claim 1 comprising the polymer and optionally a lithium salt, wherein said electrolyte is a solid polymer electrolyte (SPE) or a gel electrolyte composition.

26. The electrolyte of claim 25 , wherein the electrolyte composition further comprises a second polymer.

27. An electrolyte comprising a separator and an electrolyte composition, wherein said separator is an element as defined in claim 1 , and the electrolyte optionally further comprises a lithium salt.

28. An electrochemical cell comprising a negative electrode, a positive electrode and an electrolyte, wherein at least one of the negative electrode, positive electrode and electrolyte comprises an element as defined in claim 1 .

29. An electrochemical cell comprising a negative electrode, a positive electrode and an electrolyte, wherein at least one of the negative electrode and positive electrode comprises an electrode material as defined in claim 21 .

30. An electrochemical cell comprising a negative electrode, a positive electrode and an electrolyte, wherein the electrolyte is as defined in claim 25 .

31. An electrochemical cell comprising a negative electrode, a positive electrode and an electrolyte, wherein the electrolyte is as defined in claim 27 .

32. The electrode material of claim 22 , wherein said polymer binder is present at a concentration of up to 10 wt % in the total weight of the electrode material.

33. The electrode material of claim 23 , wherein said second polymer is selected from poly(acrylic acid), polyvinylidene fluoride, carboxymethylcellulose, styrene butadiene rubber, and a block copolymer composed of at least one lithium-ion solvating segment and at least one cross-linkable segment.

34. The electrode material of claim 24 , wherein the shell composition comprises said polymer at a concentration of between 5 wt % and 100 wt %.

35. The electrolyte of claim 25 , wherein the concentration of the polymer within the electrolyte composition is at most 50 wt %.

36. The electrolyte of claim 26 , wherein the second polymer is selected from the group consisting of a PEO-based polymer, polyvinylidene fluoride, carboxymethylcellulose, polyvinyl acetate and a polyethyleneglycol-based polymer.