Method for preparing a functionalised lithium salt

Abstract

The present invention relates to a method for preparing a lithium salt A comprising a step a) of bringing a lithium salt B, comprising at least one group –S(O)2-F, into contact with a compound C of formula (I) R-O-SiR1R2R3 in the presence of a catalyst D, in order to form a mixture of products comprising said lithium salt A comprising at least one group –S(O)2-OR. Said catalyst D is a compound having a pKa of greater than 11, measured at 25°C. The present invention also relates to a lithium salt of formula (IIIa), (IIIb), (IIIc), (IIId), (IIIe), (IIIf), (IIIg), (IIIh), (IIIi), (IIIj), (IVa), (IVb), (IVc) or (IVd).

Description

[0001] Description Title: Process for preparing a functionalized lithium salt Technical field of the invention 5 The present invention relates to a process for preparing a lithium salt. In particular, the present invention relates to a process for preparing a lithium salt carrying functional groups. Technological background of the invention 10 Li-ion batteries are used as an energy source in many devices such as mobile telephone devices, computers or electric vehicles. Most current batteries contain a liquid solution of an electrolyte consisting of a lithium salt in a solvent, the latter being generally highly flammable (for example carbonate type solvents). Other emerging technologies use an electrolyte in the form of a gel which limits the content of flammable liquid without however being risk-free.The most promising technology is based on all-solid-state batteries that do not contain flammable chemical compounds and offer high energy density. Many lithium salts are commercially available for this type of battery application. These include lithium perchlorate, lithium hexafluorophosphate, 20 bis(trifluoromethanesulfonyl)imide, and lithium bis(fluorosulfonyl)imide. Lithium sulfonyl imide salts are the most promising salts from the point of view of stability and conductivity. New lithium salts suitable for new battery technologies have been evaluated. In this regard, the implementation of polymer materials containing lithium sulfonyl imide salts has been considered. For example, WO 2016 / 012670 is known, which describes the preparation of conductive polymers of the polyaryl ether ketone or polyether sulfone type containing grafted lithium salts of bis(sulfonyl)imides.The synthesis of this type of polymer is complex and requires numerous reaction steps, sometimes with more severe operating conditions. There is therefore a need for the preparation of new lithium salts of bis(sulfonyl)imide 30 following a simple procedure and resulting in good yields. The present invention aims to resolve at least in part the drawbacks of the prior art. Summary of the invention According to a first aspect, the present invention provides a process for preparing a lithium salt A comprising a step a) of bringing a lithium salt B comprising at least one -S(O)2-F group into contact with a compound C of formula (I) RO-SiR. 1 R 2 R 3 in the presence of a catalyst D to form a mixture of products comprising said lithium salt A comprising at least one -S(O)2-OR group; said catalyst D being a compound having a pKa greater than 11 measured at 25°C.

[0002] The present invention makes it possible to prepare a functionalized lithium salt in mild operating reactions with good yields and thus avoiding side reactions. In particular, the present process makes it possible to avoid the use of nucleophilic compounds such as alkoxides or amines which leads to the dissociation of the sulfonyl imide structure. The present process makes it possible to substitute the fluorine atom carried by the sulfur atom of the lithium salt B by a functional group -OR derived from the compound C. Said lithium salt A thus formed comprises a functional group -OR linked to said sulfur atom.

[0003] According to a preferred embodiment, the substituent R of said compound C comprises at least one carbon-carbon double bond. The presence of a carbon-carbon double bond will make it possible to promote the preparation of a polymer containing the lithium salt.

[0004] According to a preferred embodiment, said lithium salt B is of formula LiN(S(O)2-F)(S(O)2R') and said lithium salt A is of formula (IV) LiN(S(O)2-OR)(S(O)2R') in which R' is a substituent selected from the group consisting of F, C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4 alkoxy, C1-C4perfluoroalkoxy; preferably C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy.

[0005] According to a preferred embodiment, said lithium salt B comprises two -S(O)2- F groups to form a lithium salt A comprising two -S(O)2-OR groups. Thus, said lithium salt A comprises two -OR groups each comprising at least one carbon-carbon double bond allowing the facilitated formation of a polymer containing a lithium salt.

[0006] According to a preferred embodiment, said lithium salt B is Li-N(S(O)2-F)2 and said lithium salt A is of formula (III) Li-N(S(O)2-OR)2.

[0007] According to a preferred embodiment, said compound C is of formula (I) RO-SiR 1 R 2 R 3 in which the R groups 1 , R 2 and R 3 are independently selected from the group consisting of H and C1-C 10 alkyl.

[0008] According to a preferred embodiment, said compound C is of formula (I) RO-SiR 1 R 2 R 3 in which the group R is of formula R 4 -X-(Y) n - in which R 4 is a radical comprising at least one carbon-carbon double bond; X is a heteroatom selected from the group consisting of O, S and N(R 5 ) in which R 5 is H or C1-C 10 alkyl; Y is a group selected from the group consisting of -C(R 6 )(R 7 )-, -C(R 6 )(R 7 )C(R 6 )(R 7 )SC(R 6 )(R 7 )- and -[(O)Z (C(R 8 )(R 9 )- C(R 8 )(R 9 )O) m -C(R 8 )(R 9 ) C(R 8 )(R 9 )]- with R 6 and R 7 independently selected for each carbon atom and for each Y unit from H or F, R 8 and R 9 independently selected for each carbon atom and for each Y unit from H, F or CH3, m an integer from 1 to 50, z = 0 if X is O; n is an integer from 1 to 50.

[0009] According to a preferred embodiment, the group R 4 is of formula (la), (Ib), (le) or (Id): in which

[0010] A, B and V are independently selected from the group consisting of

[0011] H, F, Cl, Br, I, C1-C 10 alkyl optionally substituted by one or more substituent(s) R", C2- C 10alkenyl optionally substituted by one or more substituent(s) R", C3-C 10 cycloalkyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C4-C groups 10 cycloalkenyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C6-C groups 12 aryl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl groups;

[0012] W is selected from O and S

[0013] R" is selected from the group consisting of F, Cl, I, Br, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester.

[0014] According to a preferred embodiment, said catalyst D is selected from the group consisting of N,N-Diisopropylethylamine, l,8-Diazabicyclo(5.4.0)undec-7-ene, 6- (Dibutylamino)-l,8-diazabicyclo[5.4.0]undec-7-ene, l,8-Diazabicyclo[5.4.0]undec-7-ene bound to polystyrene, l,5,7-Triazabicyclo[4.4.0]dec-5-ene, 7-Methyl-l,5,7-triazabicyclo[4.4.0]dec-5-ene,

[0015] I,1,3,3-Tetramethylguanidine, 2-tert-Butyl-l,l,3,3-tetramethylguanidine, 1,5,7- Triazabicyclo[4.4.0]dec-5-ene lié à du polystyrène, 1,4-Diazabicyclo[2.2.2]octane, Quinuclidine, l,5-Diazabicyclo(4.3.0)non-5-ene, 2,6-Di-tert-butylpyridine, 2,8,9-Trimethyl-2,5,8,9-tetraza-l- phosphabicyclo[3.3.3]undecane, Cyclodiphosphazane, Lithium diisopropylamide, sodium diisopropylamide, potassium diisopropylamide, magnesium diisopropylamide, calcium diisopropylamide, rubidium diisopropylamide, lithium bis(trimethylsilyl)amide, sodium bis(trimethylsilyl)amide, potassium bis(trimethylsilyl)amide, magnesium bis(trimethylsilyl)amide, calcium bis(trimethylsilyl)amide, rubidium bis(trimethylsilyl)amide, lithium tetramethylpiperidide, sodium tetramethylpiperidide, potassium tetramethylpiperidide, magnesium tetramethylpiperidide, calcium tetramethylpiperidide, rubidium tetramethylpiperidide, [18-crown-6]-KHF2, KHF2, N,N'-diisopropylimidazonium, bifluorure, tetra butylammonium.

[0016] According to a preferred embodiment, said method also comprises a step b) of purifying said lithium salt A; said step b) comprising the extraction of said lithium salt A with a non-polar organic solvent. According to a preferred embodiment, step a) is carried out at a temperature of 10 to 50°C.

[0017] According to a second aspect, the present invention provides a lithium salt of formula (IIIa), (II Ib),

[0018] (Illc), (llld), (llle), (lllf), (lllg), (lllh), (llli), (lllj), (IVa), (IVb), (IVc) or (IVd)

[0019] wherein the substituents A, B, V and W are as defined above according to the present invention; the substituents X, Y are as defined above according to the present invention; and n is as defined above according to the present invention and R' is as defined above according to the present invention.

[0020] According to a preferred embodiment, said lithium salt is of formula (IIIa), (I II b), (I Ile), (llld), (llle), (lllf), (Il Ig), (lllh), (llli), (lllj), (IVa), (IVb), (IVc) or (IVd) in which

[0021] A and B are the same and are selected from the group consisting of H, F, Cl, Br and I;

[0022] Y is selected from the group consisting of H, F, Cl, Br, I, C1-C 10 alkyl optionally substituted by one or more substituent(s) R", C2-C 10 alkenyl optionally substituted by one or more substituent(s) R", C3-C 10 cycloalkyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C4-C groups 10 cycloalkenyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C6-C groups 12aryl optionally substituted with one or more substituent(s) R" or one or more C1-C5alkyl groups with R" being selected from the group consisting of F, Cl, I, Br, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester; preferably V is selected from the group consisting of H, F, Cl, Br, I, C1-C5alkyl C1-C5perfluoroalkyl, C6R 10 6 with R 10 independently selected from H, F, C1-C5alkyl;

[0023] W is O;

[0024] X is O;

[0025] Y is a group selected from the group consisting of CH2CH2, CH2CF2, CF2CF2, CH2CHF, CF2CH2, CHFCH2, and n is an integer from 1 to 25; or

[0026] Y is a grouping -[(C(R 8 )(R 9 )-C(R 8 )(R 9 )O) m -C(R 8 )(R 9 )C(R 8 )(R 9 )]- with R 8 and R 9independently selected for each carbon atom and for each Y unit from H, F or CH3, m is an integer from 1 to 25 and n is 1;

[0027] R' is a substituent selected from the group consisting of F, C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy; preferably C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy. According to a preferred embodiment, said lithium salt is of formula (IIIa), (I II b), (II le), (IIId), (IIIe), (II If), (11 Ig), (I II h), (II li), (IIIj), (IVa), (IVb), (IVc) or (IVd) in which A and B are H, V is CH3, W is O, X is O and Y is a group selected from the group consisting of CH2CH2, CH2CF2, CF2CF2, CH2CHF, CF2CH2, CHFCH2, and n is an integer from 1 to 10; or

[0028] Y is a grouping -[(C(R 8 )(R 9 )-C(R 8 )(R 9 )O) m -C(R 8 )(R 9 )C(R 8 )(R 9 )]- with R8 and R 9 independently selected for each carbon atom and for each Y unit from H, F or CH3, m is an integer from 1 to 25 and n is 1;

[0029] R' is a substituent selected from the group consisting of F, C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy; preferably C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy.

[0030] According to a preferred embodiment, said lithium salt is of formula (IIIa) in which A and B are H, V is CH3, W is O, X is O and Y is a group selected from the group consisting of CH2CH2, CH2CF2, CF2CF2, CH2CHF, CF2CH2, CHFCH2, and n is an integer from 1 to 10; or

[0031] Y is a grouping -[(C(R 8 )(R 9 )-C(R 8 )(R 9 )O) m -C(R 8 )(R 9 )C(R 8 )(R 9 )]- with R 8 and R 9independently selected for each carbon atom and for each Y unit from H, F or CH3, m is an integer from 1 to 25 and n is 1.

[0032] According to another aspect, the present invention provides a polymer comprising monomeric units derived from at least one lithium salt of formula (IIIa), (IIb), (IIe), (IIId), (IIIe), (IIf), (IIIg), (IIIh), (IIIi), (IIIj), (IVa), (IVb), (IVc) or (IVd) according to the present invention.

[0033] According to a preferred embodiment, said polymer also comprises monomeric units derived from a monomer M1 of formula R 1 R 2 C=C(R 3 )C(O)R in which the substituents R 1 , R 2 and R 3are independently of each other selected from the group consisting of H and C1-C5alkyl; R is selected from the group consisting of - NHC(CH3)2CH2C(O)CH3OR -OR' with R' selected from the group consisting of H and C1-C1s alkyl optionally substituted with one or more -OH groups or a five- or ten-membered heterocycle comprising at least one nitrogen atom in its ring chain.

[0034] According to a preferred embodiment, said polymer also comprises monomeric units derived from a monomer M2 selected from the group consisting of vinylidene fluoride, vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoro(alkyl vinyl) ethers, perfluoro(1,3-dioxole), perfluoro(2,2-dimethyl-1,3-dioxole), the monomer of formula CF2=CFOCF2CF(CF3)OCF2CF2X in which X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H, the monomer of formula CF2=CFOCF2CF2SO2F, the monomer of formula F(CF2)nCH2OCF=CF2in which n is 1, 2, 3, 4 or 5, the monomer of formula R 1 CH2OCF=CF2in which R 1 is hydrogen or F(CF2)m and m is 1, 2, 3 or 4, the monomer of formula R 2 OCF=CH2in which R 2is F(CF2)p and p is 1, 2, 3 or 4, perfluorobutyl ethylene, trifluoropropene, tetrafluoropropene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropene, 2-trifluoromethyl- 3,3,3-trifluoro-l-propene.

[0035] According to a preferred embodiment, the present invention provides a binder for an electrode or coating for a separator comprising said polymer according to the present invention.

[0036] According to a preferred embodiment, the present invention provides an electrode or a separator comprising said polymer according to the present invention.

[0037] According to a preferred embodiment, the present invention provides a battery, preferably lithium-ion, comprising said electrode or said separator according to the present invention.

[0038] Detailed description of the invention

[0039] According to a first aspect of the invention, a process for preparing a lithium salt A is provided. Said process comprises a step of bringing a lithium salt B comprising at least one -S(O)2-F group into contact with a compound C of formula (I) RO-SiR 1 R 2 R 3 . Said lithium salt A is formed by an exchange reaction between the fluorine atom carried by the —S(O)2- group of said lithium salt B and the —OR group derived from compound C and carried by the silicon atom thereof. Said lithium salt A thus formed comprises at least one —S(O)2- OR group. Said method according to the present invention also results in the formation of a coproduct F-SiR 1 R 2 R 3. The present process avoids the formation of HF (the fluorine atom bonding to the Si atom) during the reaction which would have required its neutralization by an excess of base or additional purification steps. The present invention makes it possible to prepare a functionalized lithium salt in mild operating reactions with good yields and thus avoiding side reactions.

[0040] Compound B

[0041] As mentioned above, said lithium salt B comprises at least one -S(O)2-F group. According to a preferred embodiment, said lithium salt B is of formula LiN(S(O)2-F)(S(O)2R') in which R' is a substituent selected from the group consisting of F, C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy; preferably C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy. Thus, preferably, the present method comprises a step of bringing LiN(S(O)2-F)(S(O)2R') into contact with a compound C of formula (I) RO-SiR x R 2 R 3 as defined in the present application, preferably in the presence of catalyst D as defined in the present application.

[0042] Preferably, said lithium salt B comprises two -S(O)2-F groups.

[0043] In particular, said lithium salt B is Li-N(S(O)2-F)2, i.e. lithium bis(sulfonyl)imide also called LiFSI. Thus, preferably, the present method comprises a step of bringing Li-N(S(O)2-F)2 into contact with a compound C of formula (I) RO-SiR 1 R 2 R 3 as defined in the present application, preferably in the presence of catalyst D as defined in the present application.

[0044] Compound C

[0045] According to a preferred embodiment, said compound C is of formula (I) RO-SiR 1 R 2 R 3 .

[0046] According to a preferred embodiment, said compound C is of formula (I) RO-SiR 1 R 2 R 3 in which the R groups 1 , R 2 and R 3 are independently of each other selected from the group consisting of H, C1-C 20 alkyl, C3-C 20 cycloalkyl, C6-C 20aryl. Preferably, the R groups 1 , R 2 and R 3 are independently of each other selected from the group consisting of H, C1-C15 alkyl, C3-C15 cycloalkyl, C6-C 15 aryl. More preferably, the R groups 1 , R 2 and R 3 are independently of each other selected from the group consisting of H, C1-C 10 alkyl, C3-C 10 cycloalkyl, C6-C 12 aryl. In particular, the R groups 1 , R 2 and R 3 are independently selected from the group consisting of H and C1-C 10 alkyl. More particularly, the R groups 1 , R 2 and R 3 are independently of each other selected from the group consisting of H, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, sec-butyl, pentyl. Preferably, the groups R 1 , R2 and R 3 are independently of each other selected from the group consisting of H, methyl, ethyl, propyl, tert-butyl. Preferably, the groups R 1 and R 2 are identical and are selected from the group consisting of H, methyl, ethyl and the group R 3 is selected from the group consisting of H, methyl, ethyl, propyl, tert-butyl. In a particularly preferred manner, the groups R 1 , R 2 and R 3 are identical and are selected from the group consisting of H, methyl, ethyl.

[0047] According to a preferred embodiment, the substituent R of said compound C comprises at least one carbon-carbon double bond. As mentioned above, the presence of a carbon-carbon double bond will make it possible to promote the preparation of a polymer containing the lithium salt. Preferably, the group R of said compound C is of formula R -X-(Y) n - in which

[0048] R 4 is a radical comprising at least one carbon-carbon double bond;

[0049] X is a heteroatom selected from the group consisting of O, S and N(R 5 ) in which R 5 is H or C1-C 10 alkyl; preferably R 5 is H, CH3 or C2H5;

[0050] Y is a group selected from the group consisting of -C(R 6 )(R 7 )-, - C(R 6 )(R 7 )C(R 6 )(R 7 )SC(R 6 )(R 7 )- and -[(O) z (C(R 8 )(R 9 )-C(R8 )(R 9 )O) m -C(R 8 )(R 9 )C(R 8 )(R 9 )]- with

[0051] R 6 and R 7 independently selected for each carbon atom and for each Y unit from H or F; R 8 and R 9 independently selected for each carbon atom and for each unit Y from H, F or CH3, m an integer from 1 to 50, advantageously from 1 to 40, preferably from 1 to 30, more preferably from 1 to 20, in particular from 1 to 10. z = 0 if X is O; n is an integer from 1 to 50, advantageously from 1 to 40, preferably from 1 to 30, more preferably from 1 to 20, in particular from 1 to 10.

[0052] According to a preferred embodiment, in said compound C, the group R 4 is of formula (la), (Ib), (le) or (Id): in which

[0053] A, B and V are independently selected from the group consisting of H, F, Cl, Br, I, C1-C 20 alkyl optionally substituted by one or more substituent(s) R", C2- C 20 alkenyl optionally substituted by one or more substituent(s) R", C3-C 20 cycloalkyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C4-C groups 20 cycloalkenyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C6-C groups 20 aryl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl groups;

[0054] W is selected from O and S, preferably O;

[0055] R" is selected from the group consisting of F, Cl, I, Br, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester, preferably F, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester. Preferably, in said compound C, the group R 4 is of formula (Ia), (Ib), (Ic) or (Id) as illustrated above wherein A, B and V are independently of each other selected from the group consisting of H, F, Cl, Br, I, C1-C15 alkyl optionally substituted with one or more substituent(s) R", C2-C 15 alkenyl optionally substituted by one or more substituent(s) R", C3-C 15 cycloalkyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C4-C groups 15 cycloalkenyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C6-C groups 15aryl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl groups;

[0056] W is selected from O and S, preferably O;

[0057] R" is selected from the group consisting of F, Cl, I, Br, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester, preferably F, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester.

[0058] More preferably, in said compound C, the group R 4 is of formula (Ia), (Ib), (Ic) or (Id) as illustrated above in which A, B and V are independently of each other selected from the group consisting of H, F, Cl, Br, I, C1-C 10 alkyl optionally substituted by one or more substituent(s) R", C2-C 10 alkenyl optionally substituted by one or more substituent(s) R", C3-C 10cycloalkyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C4-C groups 10 cycloalkenyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C6-C groups 10 aryl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl groups;

[0059] W is selected from O and S, preferably O;

[0060] R" is selected from the group consisting of F, Cl, I, Br, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester, preferably F, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester.

[0061] In particular, in said compound C, the group R 4 is of formula (Ia), (Ib), (Ic) or (Id) as illustrated above in which A, B and V are independently of each other selected from the group consisting of H, F, Cl, Br, I, C1-C 10 alkyl, C2-C10 alkenyl, C3-C 10 cycloalkyl, C4-C 10 cycloalkenyl, C6-C 10 aryl, C1-C 10 perfluoroalkyl, C2-C 10 perfluoroalkenyl, C3-C 10 perfluorocycloalkyl, C4-C 10 perfluorocycloalkenyl, C6R 10 5 with R 10 independently selected from H, F, C1-C5alkyl;

[0062] W is selected from O and S, preferably O. More particularly, in said compound C, the group R 4 is of formula (Ia), (Ib), (Ic) or (Id) as illustrated above in which A, B and V are independently of each other selected from the group consisting of H, F, Cl, Br, I, C1-C5alkyl, C1-C5perfluoroalkyl, C6R 10 5 with R 10 independently selected from H, F, C1-C5alkyl;

[0063] W is selected from O and S, preferably O.

[0064] Preferably, in said compound C, the group R 4is of formula (Ia), (Ib), (Ic) or (Id) as illustrated above wherein A and B are independently of each other selected from the group consisting of H, F, Cl, I, Br, CH3, C2H5, CF3, C2F5, phenyl; and V is selected from the group consisting of H, F, Cl, Br, I, C1-C5alkyl, C1-C5perfluoroalkyl, C6R 10 5 with R 10 independently selected from H, F, C1-C5alkyl;

[0065] W is selected from O and S, preferably O.

[0066] In a preferential manner, the R group 4 is of formula (la), (Ib), (le) or (Id) as illustrated above in which

[0067] A and B are the same and are selected from the group consisting of H, F, Cl, I, Br; or

[0068] A is H and B is selected from the group consisting of F, Cl, Br, I, CH3, C2H5, CF3, C2F5, phenyl.

[0069] V is selected from the group consisting of H, F, Cl, Br, I, C1-C5alkyl, C1-C5perfluoroalkyl, C6R 10 5 with R 10 independently selected from H, F, C1-C5alkyl;

[0070] W is selected from O and S, preferably O.

[0071] Thus, according to the present invention, said compound C may be of formula (Ia), (Ib), (Ic) or (Id)

[0072] in which the substituents A, B, V, W, X, Y, R 1 , R 2 and R 3 are as defined above in the present application according to any of the embodiments described. According to a preferred embodiment, said compound C may be of formula (Ia), (Ib), (Ic) or (Id) in which

[0073] R 1 , R 2 and R 3are independently of each other selected from the group consisting of H, C1-C 20 alkyl, C3-C 20 cycloalkyl, C6-C 20 aryl; advantageously R 1 , R 2 and R 3 are independently of each other selected from the group consisting of H, C1-C 15 alkyl, C3-C 15 cycloalkyl, C6-C 15 aryl; preferably R 1 , R 2 and R 3 are independently of each other selected from the group consisting of H, C1-C 10 alkyl, C3-C 10 cycloalkyl, C6-C 12 aryl; more preferably R 1 , R 2 and R 3 are independently selected from the group consisting of H and C1-C 10 alkyl; in particular R 1 , R 2 and R 3are independently of each other selected from the group consisting of H, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, sec-butyl, pentyl; more particularly R 1 , R 2 and R 3 are independently of each other selected from the group consisting of H, methyl, ethyl, propyl, tert-butyl;

[0074] X is a heteroatom selected from the group consisting of O, S and N(R 5 ) in which R 5 is H or C1-C 10 alkyl;

[0075] Y is a group selected from the group consisting of -C(R 6 )(R 7 )-, - C(R 6 )(R 7 )C(R 6 )(R 7 )SC(R 6 )(R 7 )- and -[(O) z (C(R 8 )(R 9 )-C(R 8 )(R 9 )O) m -C(R 8 )(R 9 )C(R 8 )(R 9 )]- with R 6 and R 7independently selected for each carbon atom and for each Y unit from H or F; R 8 and R 9 independently selected for each carbon atom and for each unit Y from H, F or CH3; m an integer from 1 to 50, advantageously from 1 to 40, preferably from 1 to 30, more preferably from 1 to 20, in particular from 1 to 10; z = 0 if X is O; n is an integer from 1 to 50, advantageously from 1 to 40, preferably from 1 to 30, more preferably from 1 to 20, in particular from 1 to 10;

[0076] A, B and V are independently selected from the group consisting of H, F, Cl, Br, I, C1-C 20 alkyl optionally substituted by one or more substituent(s) R", C2- C 20 alkenyl optionally substituted by one or more substituent(s) R", C3-C 20 cycloalkyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C4-C groups 20cycloalkenyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C6-C groups 20 aryl optionally substituted with one or more substituent(s) R" or one or more C1-C5alkyl groups with R" selected from the group consisting of F, Cl, I, Br, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester, preferably F, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester; advantageously A, B and V are independently of each other selected from the group consisting of H, F, Cl, Br, I, C1-C 15 alkyl optionally substituted by one or more substituent(s) R", C2-C 15 alkenyl optionally substituted by one or more substituent(s) R", C3-C 15 cycloalkyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C4-C groups 15cycloalkenyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C6-C groups 15 aryl optionally substituted with one or more substituent(s) R" or one or more C1-C5alkyl groups with R" selected from the group consisting of F, Cl, I, Br, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester, preferably F, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester; preferably A, B and

[0077] V are independently selected from the group consisting of H, F, Cl, Br, I, C1-C 10 alkyl optionally substituted by one or more substituent(s) R", C2-C 10 alkenyl optionally substituted by one or more substituent(s) R", C3-C 10 cycloalkyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C4-C groups 10cycloalkenyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C6-C groups 10 aryl optionally substituted with one or more substituent(s) R" or one or more C1-C5alkyl groups with R" selected from the group consisting of F, Cl, I, Br, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester, preferably F, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester; more preferably A, B and V are independently of each other selected from the group consisting of H, F, Cl, Br, I, C1-C 10 alkyl, C2-C 10 alkenyl, C3-C 10 cycloalkyl, C4-C 10 cycloalkenyl, C6-C 10 aryl, C1-C 10 perfluoroalkyl, C2-C 10 perfluoroalkenyl, C3-C 10 perfluorocycloalkyl, C4-C 10 perfluorocycloalkenyl, C6-C 10 perfluoroaryl; in particular A, B and

[0078] V are independently of each other selected from the group consisting of H, F, Cl, Br, I, C1-C5alkyl, C1-C5perfluoroalkyl, C6R 10 s with R 10 independently selected from H, F, C1-C5alkyl;

[0079] W is selected from O and S, preferably O.

[0080] According to a particular embodiment, said compound C may be of formula (Ia), (Ib), (Ic) or (Id)

[0081] in which

[0082] R 1 and R 2 are identical and are selected from the group consisting of H, methyl, ethyl and R 3 is selected from the group consisting of H, methyl, ethyl, propyl, tert-butyl; preferably, R 1 , R 2 and R 3 are the same and are selected from the group consisting of H, methyl, ethyl; X is a heteroatom selected from the group consisting of O, S and N(R 5 ) in which R 5is H or C1-C 10 alkyl; preferably R 5 is H, CH3 or C2H5;

[0083] Y is a group selected from the group consisting of -C(R 6 )(R 7 )-, - C(R 6 )(R 7 )C(R 6 )(R 7 )SC(R 6 )(R 7 )- and -[(O) z (C(R 8 )(R 9 )-C(R 8 )(R 9 )O) m -C(R 8 )(R 9 )C(R 8 )(R 9 )]- with R 6 and R 7 independently selected for each carbon atom and for each Y unit from H or F; R 8 and R 9independently selected for each carbon atom and for each unit Y from H, F or CH3; m an integer from 1 to 50, advantageously from 1 to 40, preferably from 1 to 30, more preferably from 1 to 20, in particular from 1 to 10; z = 0 if X is O; n is an integer from 1 to 50, advantageously from 1 to 40, preferably from 1 to 30, more preferably from 1 to 20, in particular from 1 to 10;

[0084] A and B are independently of each other selected from the group consisting of H, F, Cl, I, Br, CH3, C2H5, CF3, C2F5, phenyl; preferably A and B are the same and are selected from the group consisting of H, F, Cl, I, Br or A is H and B is selected from the group consisting of F, Cl, Br, I, CH3, C2H5, CF3, C2F5, phenyl;

[0085] V is selected from the group consisting of H, F, Cl, Br, I, C1-C5alkyl, C1-C5perfluoroalkyl, C6R 10 5 with R 10 independently selected from H, F, C1-C5alkyl;

[0086] W is selected from O and S, preferably O.

[0087] Compound A

[0088] As mentioned above, said lithium salt A is formed by an exchange reaction between the fluorine atom of the S(O)2F group carried by said lithium salt B and said -OR group derived from said compound C of formula (I) RO-SiR 1 R 2 R 3 .

[0089] According to a preferred embodiment, said lithium salt A comprises at least one -S(O)2-0R group. Preferably, said lithium salt A comprises two -S(O)2-0R groups when said lithium salt B comprises two -S(O)2-F groups. Thus, said lithium salt A comprises two -OR groups each comprising at least one carbon-carbon double bond allowing the facilitated formation of a polymer containing a lithium salt.

[0090] According to a particular embodiment, said lithium salt A is of formula (III) Li-N(S(O)2-OR)2 with R of formula R 4 -X-(Y) n - in which R 4 is a radical comprising at least one carbon-carbon double bond; X is a heteroatom selected from the group consisting of O, S and N(R 5 ) in which R 5 is H or C1-C 10 alkyl; preferably R 5 is H, CH3 or C2H5; Y is a group selected from the group consisting of -C(R 6 )(R 7 )-, C(R 6 )(R 7 )C(R 6 )(R 7 )SC(R 6 )(R 7 )- and -[(O) z (C(R 8 )(R 9 )-C(R 8 )(R 9 )O) m -C(R 8 )(R 9 )C(R 8 )(R 9 )]- with R 6 and R 7 independently selected for each carbon atom and for each Y unit from H or F; R 8 and R 9independently selected for each carbon atom and for each unit Y from H, F or CH3; m an integer from 1 to 50, advantageously from 1 to 40, preferably from 1 to 30, more preferably from 1 to 20, in particular from 1 to 10; z = 0 if X is O; n is an integer from 1 to 50, advantageously from 1 to 40, preferably from 1 to 30, more preferably from 1 to 20, in particular from 1 to 10.

[0091] When said lithium salt A is of formula (III) Li-N(S(O)2-OR)2, the substituents R are selected independently of each other for each of the functional groups S(O)2-OR.

[0092] Thus, according to a preferred embodiment, said lithium salt A is of formula (IIIa), (IIIb), (11e),

[0093] (Illd), (llle), (lllf), (lllg), (lllh), (llli) or (lllj):

[0094] in which

[0095] X is a heteroatom selected from the group consisting of O, S and N(R5 ) in which R 5 East

[0096] H or C1-C 10 alkyl;

[0097] Y is a group selected from the group consisting of -C(R 6 )(R 7 )-, - C(R 6 )(R 7 )C(R 6 )(R 7 )SC(R 6 )(R 7 )- and -[(O) z (C(R 8 )(R 9 )-C(R 8 )(R 9 )O) m -C(R 8 )(R 9 )C(R 8 )(R 9 )]- with R 6 and R 7 independently selected for each carbon atom and for each Y unit from H or F; R 8 and R 9independently selected for each carbon atom and for each unit Y from H, F or CH3; m an integer from 1 to 50, advantageously from 1 to 40, preferably from 1 to 30, more preferably from 1 to 20, in particular from 1 to 10; z = 0 if X is O; n is an integer from 1 to 50, advantageously from 1 to 40, preferably from 1 to 30, more preferably from 1 to 20, in particular from 1 to 10;

[0098] A, B and V are independently selected from the group consisting of H, F, Cl, Br, I, C1-C 20 alkyl optionally substituted by one or more substituent(s) R", C2- C 20 alkenyl optionally substituted by one or more substituent(s) R", C3-C 20 cycloalkyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C4-C groups 20 cycloalkenyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C6-C groups20 aryl optionally substituted with one or more substituent(s) R" or one or more C1-C5alkyl groups with R" selected from the group consisting of F, Cl, I, Br, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester, preferably F, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester; advantageously A, B and V are independently of each other selected from the group consisting of H, F, Cl, Br, I, C1-C15 alkyl optionally substituted by one or more substituent(s) R", C2-C15 alkenyl optionally substituted by one or more substituent(s) R", C3-C15 cycloalkyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl groups, C4-C15 cycloalkenyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl groups, C6-C 15aryl optionally substituted with one or more substituent(s) R" or one or more C1-C5alkyl groups with R" selected from the group consisting of F, Cl, I, Br, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester, preferably F, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester; preferably A, B and V are independently of each other selected from the group consisting of H, F, Cl, Br, I, C1-C 10 alkyl optionally substituted by one or more substituent(s) R", C2-C 10 alkenyl optionally substituted by one or more substituent(s) R", C3-C 10 cycloalkyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C4-C groups 10 cycloalkenyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C6-C groups 10aryl optionally substituted with one or more substituent(s) R" or one or more C1-C5alkyl groups with R" selected from the group consisting of F, Cl, I, Br, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester, preferably F, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester; more preferably A, B and V are independently of each other selected from the group consisting of H, F, Cl, Br, I, C1-C 10 alkyl, C2-C 10 alkenyl, C3-C 10 cycloalkyl, C4-C 10 cycloalkenyl, C6-C 10 aryl, C1-C 10 perfluoroalkyl, C2-C 10 perfluoroalkenyl, C3-C 10 perfluorocycloalkyl, C4-C 10 perfluorocycloalkenyl, C6-C 10 perfluoroaryl; in particular A, B and

[0099] V are independently of each other selected from the group consisting of H, F, Cl, Br, I, C1-C5alkyl, C1-C5perfluoroalkyl, C6R 10 5 with R 10independently selected from H, F, C1-C5alkyl;

[0100] W is selected from O and S, preferably O.

[0101] Preferably, said lithium salt A is of formula (IIIa), (III b), (Il le), (Il Id), (Ile), (Ile If), (Illg), (Il Ih), (llli) or (lllj) in which

[0102] X is a heteroatom selected from the group consisting of O, S and N(R 5 ) in which R 5 is H or C1-C 10 alkyl; preferably R 5 is H, CH3 or C2H5;

[0103] V is a group selected from the group consisting of -C(R 6 )(R 7 )-, - C(R 6 )(R 7 )C(R 6 )(R 7 )SC(R 6 )(R 7 )- and -[(O) z (C(R 8 )(R 9 )-C(R 8 )(R 9 )O) m -C(R 8 )(R 9 )C(R 8 )(R 9 )]- with R 6 and R 7independently selected for each carbon atom and for each Y unit from H or F; R 8 and R 9 independently selected for each carbon atom and for each unit Y from H, F or CH3; m an integer from 1 to 50, advantageously from 1 to 40, preferably from 1 to 30, more preferably from 1 to 20, in particular from 1 to 10; z = 0 if X is O; n is an integer from 1 to 50, advantageously from 1 to 40, preferably from 1 to 30, more preferably from 1 to 20, in particular from 1 to 10;

[0104] A and B are independently of each other selected from the group consisting of H, F, Cl, I, Br, CH3, C2H5, CF3, C2F5, phenyl; preferably A and B are the same and are selected from the group consisting of H, F, Cl, I, Br or A is H and B is selected from the group consisting of F, Cl, Br, I, CH3, C2H5, CF3, C2F5, phenyl;

[0105] V is selected from the group consisting of H, F, Cl, Br, I, C1-C5alkyl, C1-C5perfluoroalkyl, C6R 10 5 with R 10 independently selected from H, F, C1-C5alkyl;

[0106] W is selected from O and S, preferably O.

[0107] In particular, said lithium salt A is of formula (IIIa), (I II b), (II le) or (IIIld) as defined above.

[0108] Alternatively, said lithium salt A is of formula (IV) LiN(S(O)2-OR)(S(O)2R') when said lithium salt B is of formula LiN(S(O)2-F)(S(O)2R'). Said lithium salt A is of formula (IV) LiN(S(O)2-OR)(S(O)2R') wherein R' is a substituent selected from the group consisting of F, C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy and R is as defined above in the present application.

[0109] Thus, said lithium salt A is of formula (IV) LiN(S(O)2-OR)(S(O)2R') in which

[0110] R' is a substituent selected from the group consisting of F, C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy; preferably C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy;

[0111] R is of formula R 4 -X-(Y) n - in which R 4 is a radical comprising at least one carbon-carbon double bond; X is a heteroatom selected from the group consisting of O, S and N(R 5 ) in which R 5 is H or C1-C 10 alkyl; preferably R 5 is H, CH3 or C2H5; Y is a group selected from the group consisting of -C(R 6 )(R 7 )-, C(R 6 )(R 7 )C(R 6 )(R 7 )SC(R 6 )(R 7 )- and -[(O) z (C(R 8 )(R 9 )-C(R 8 )(R 9 )O) m -C(R 8 )(R 9 )C(R 8 )(R 9 )]- with R 6 and R7 independently selected for each carbon atom and for each Y unit from H or F; R 8 and R 9 independently selected for each carbon atom and for each unit Y from H, F or CH3; m an integer from 1 to 50, advantageously from 1 to 40, preferably from 1 to 30, more preferably from 1 to 20, in particular from 1 to 10; z = 0 if X is O; n is an integer from 1 to 50, advantageously from 1 to 40, preferably from 1 to 30, more preferably from 1 to 20, in particular from 1 to 10

[0112] Thus, said lithium salt A is of formula (IVa), (IVb), (IVc) or (IVd)

[0113] in which

[0114] X is a heteroatom selected from the group consisting of O, S and N(R 5 ) in which R 5 is H or C1-C 10 alkyl;

[0115] Y is a group selected from the group consisting of -C(R 6 )(R 7)-, - C(R 6 )(R 7 )C(R 6 )(R 7 )SC(R 6 )(R 7 )- and -[(O) z (C(R 8 )(R 9 )-C(R 8 )(R 9 )O) m -C(R 8 )(R 9 )C(R 8 )(R 9 )]- with R 6 and R 7 independently selected for each carbon atom and for each Y unit from H or F; R 8 and R 9 independently selected for each carbon atom and for each unit Y from H, F or CH3; m an integer from 1 to 50, advantageously from 1 to 40, preferably from 1 to 30, more preferably from 1 to 20, in particular from 1 to 10; z = 0 if X is O; n is an integer from 1 to 50, advantageously from 1 to 40, preferably from 1 to 30, more preferably from 1 to 20, in particular from 1 to 10;

[0116] A, B and V are independently selected from the group consisting of H, F, Cl, Br, I, C1-C 20alkyl optionally substituted by one or more substituent(s) R", C2- C 20 alkenyl optionally substituted by one or more substituent(s) R", C3-C 20 cycloalkyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C4-C groups 20 cycloalkenyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C6-C groups 20 aryl optionally substituted with one or more substituent(s) R" or one or more C1-C5alkyl groups with R" selected from the group consisting of F, Cl, I, Br, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester, preferably F, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester; advantageously A, B and V are independently of each other selected from the group consisting of H, F, Cl, Br, I, C1-C 15 alkyl optionally substituted by one or more substituent(s) R", C2-C 15alkenyl optionally substituted by one or more substituent(s) R", C3-C 15 cycloalkyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C4-C groups 15 cycloalkenyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C6-C groups 15 aryl optionally substituted with one or more substituent(s) R" or one or more C1-C5alkyl groups with R" selected from the group consisting of F, Cl, I, Br, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester, preferably F, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester; preferably A, B and

[0117] V are independently selected from the group consisting of H, F, Cl, Br, I, C1-C 10 alkyl optionally substituted by one or more substituent(s) R", C2-C 10alkenyl optionally substituted by one or more substituent(s) R", C3-C 10 cycloalkyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C4-C groups 10 cycloalkenyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C6-C groups 10 aryl optionally substituted with one or more substituent(s) R" or one or more C1-C5alkyl groups with R" selected from the group consisting of F, Cl, I, Br, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester, preferably F, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester; more preferably A, B and V are independently of each other selected from the group consisting of H, F, Cl, Br, I, C1-C 10 alkyl, C2-C 10 alkenyl, C3-C 10 cycloalkyl, C4-C 10 cycloalkenyl, C6-C 10 aryl, C1-C 10 perfluoroalkyl, C2-C 10perfluoroalkenyl, C3-C 10 perfluorocycloalkyl, C4-C 10 perfluorocycloalkenyl, C6-C 10 perfluoroaryl; in particular A, B and

[0118] V are independently of each other selected from the group consisting of H, F, Cl, Br, I, C1-C5alkyl, C1-C5perfluoroalkyl, C6R 10 5 with R 10 independently selected from H, F, C1-C5alkyl;

[0119] W is selected from O and S, preferably O;

[0120] R' is a substituent selected from the group consisting of F, C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy; preferably C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy.

[0121] Preferably, said lithium salt A is of formula (IVa), (IVb), (IVc) or (IVd) in which

[0122] X is a heteroatom selected from the group consisting of O, S and N(R 5 ) in which R 5is H or C1-C 10 alkyl; preferably R 5 is H, CH3 or C2H5; Y is a group selected from the group consisting of -C(R 6 )(R 7 )-, - C(R 6 )(R 7 )C(R 6 )(R 7 )SC(R 6 )(R 7 )- and -[(O) z (C(R 8 )(R 9 )-C(R 8 )(R 9 )O) m -C(R 8 )(R 9 )C(R 8 )(R 9 )]- with R 6 and R 7 independently selected for each carbon atom and for each Y unit from H or F; R 8 and R 9independently selected for each carbon atom and for each unit Y from H, F or CH3; m an integer from 1 to 50, advantageously from 1 to 40, preferably from 1 to 30, more preferably from 1 to 20, in particular from 1 to 10; z = 0 if X is O; n is an integer from 1 to 50, advantageously from 1 to 40, preferably from 1 to 30, more preferably from 1 to 20, in particular from 1 to 10;

[0123] A and B are independently of each other selected from the group consisting of H, F, Cl, I, Br, CH3, C2H5, CF3, C2F5, phenyl; preferably A and B are the same and are selected from the group consisting of H, F, Cl, I, Br or A is H and B is selected from the group consisting of F, Cl, Br, I, CH3, C2H5, CF3, C2F5, phenyl;

[0124] V is selected from the group consisting of H, F, Cl, Br, I, C1-C5alkyl, C1-C5perfluoroalkyl, C6R 10 5 with R 10 independently selected from H, F, C1-C5alkyl;

[0125] W is selected from O and S, preferably O;

[0126] R' is a substituent selected from the group consisting of F, C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy; preferably C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy.

[0127] Catalyst D

[0128] Said process for preparing said lithium salt A is carried out in the presence of a catalyst D. Advantageously, said catalyst D is a non-nucleophilic compound. The use of a non-nucleophilic compound makes it possible to avoid the degradation of said lithium salt B.

[0129] According to a preferred embodiment, said catalyst D is a compound having a pKa greater than 11 measured at 25°C in water. According to a particular embodiment, said catalyst D has a pKa greater than 11.5, advantageously greater than 12.0, preferably greater than 12.5, in particular greater than 13.0.

[0130] Preferably, the molar ratio of the catalyst relative to said lithium salt B is greater than or equal to 0.1, preferably greater than or equal to 0.2. Preferably, the molar ratio of the catalyst relative to said lithium salt B is less than or equal to 2.5, preferably less than or equal to 2. According to a preferred embodiment, said catalyst D is selected from the group consisting of N,N-Diisopropylethylamine, l,8-Diazabicyclo(5.4.0)undec-7-ene, 6- (Dibutylamino)-l,8-diazabicyclo[5.4.0]undec-7-ene, l,8-Diazabicyclo[5.4.0]undec-7-ene bound to polystyrene, l,5,7-Triazabicyclo[4.4.0]dec-5-ene, 7-Methyl-l,5,7-triazabicyclo[4.4.0]dec-5-ene, 1,1,3,3-Tetramethylguanidine, 2-tert-Butyl-l,l,3,3-tetramethylguanidine, 1,5,7- Triazabicyclo[4.4.0]dec-5-ene bound to polystyrene, 1,4-Diazabicyclo[2.2.2]octane, Quinuclidine, l,5-Diazabicyclo(4.3.0)non-5-ene, 2,6-Di-tert-butylpyridine, 2,8,9-Trimethyl-2,5,8,9-tetraza-l- phosphabicyclo[3.3.3]undecane, cyclodiphosphazane, Lithium diisopropylamide, sodium diisopropylamide, potassium diisopropylamide, magnesium diisopropylamide, calcium diisopropylamide, rubidium diisopropylamide, lithium bis(trimethylsilyl)amide, sodium bis(trimethylsilyl)amide, potassium bis(trimethylsilyl)amide, magnesium bis(trimethylsilyl)amide, calcium bis(trimethylsilyl)amide, rubidium bis(trimethylsilyl)amide, lithium tetramethylpiperidide, sodium tetramethylpiperidide, potassium tetramethylpiperidide, magnesium tetramethylpiperidide, calcium tetramethylpiperidide, rubidium tetramethylpiperidide, [18-crown-6]-KHF2, KHF2, N,N'-diisopropylimidazonium, bifluorure, tetra butylammonium.

[0131] In particular, said catalyst D is selected from the group consisting of 1,8-Diazabicyclo(5.4.0)undec-7-ene, 1,5,7-Triazabicyclo[4.4.0]dec-5-ene, 2-tert-butyl-1,3,3-tetramethylguanidine, 1,5,7-Triazabicyclo[4.4.0]dec-5-ene bound to polystyrene and 1,8-Diazabicyclo[5.4.0]undec-7-ene bound to polystyrene.

[0132] Implementation of the method according to the invention

[0133] The process can be carried out under mild operating conditions. Step a) of the process is preferably carried out in a reactor made of a material such as Inconel®, Hastelloy®, Monel®.

[0134] According to a preferred embodiment, said process is carried out at a temperature of 10 to 70°C, advantageously from 10°C to 50°C, preferably at a temperature of 10°C to 30°C. Said process can be carried out at a pressure of 0.5 to 3 bara, preferably at atmospheric pressure; even if the pressure is not an important parameter in the implementation of the process.

[0135] Said process can be carried out under an inert atmosphere or not. Preferably, in step a), said lithium salt B is brought into contact with said catalyst D followed by the addition of said compound C. This makes it possible to improve the conversion of the reaction between the lithium salt and the compound C.

[0136] The reaction between lithium salt B and compound C is preferably carried out at stoichiometry or in slight excess or deficiency of compound C. Thus, for example, if said lithium salt B comprises two S(0)2-F groups, 2 eq. of compound C relative to the number of moles of lithium salt B are added.

[0137] Said method can be carried out in the presence of a solvent even if the method can be carried out without solvent. When a solvent is used, it can be for example acetonitrile, benzonitrile, dimethylsulfoxide, dimethyl formamide, 1,4 dioxane, nitromethane, dimethyl carbonate, diethyl carbonate, propyl carbonate, ethylene carbonate, N-methyl-2-pyrrolidone or a mixture thereof.

[0138] In addition to lithium salt A, said product mixture may comprise said unreacted lithium salt B or said unreacted compound C or a mixture of both.

[0139] Said product mixture may also include F-SiR 1 R 2 R 3 with R 1 , R 2 and R 3 as defined in this application. When R 1 , R 2 and R 3 are CH3, the F-Si(CH3)3 formed during step a) is easily eliminated given its boiling point (Bp = 16°C).

[0140] When said lithium salt B comprises two S(O)2-F groups, said mixture of products may also comprise a compound in which only one of the fluorine atoms has been substituted. For example, when said lithium salt B is LiN(S(O)2-F)2, said mixture of products may comprise LiN(S(O)2F)(S(O)2-OR).

[0141] Said lithium salt B may optionally contain impurities linked to its preparation process, such as LiCl, LiF or FSO3Li in a mass content of less than 1000 ppm, advantageously less than 500 ppm, preferably less than 100 ppm based on the total weight of said lithium salt. In particular, FSO3Li, if present, represents a mass content of less than 5 ppm based on the total weight of said lithium salt B. Other impurities may also be present in said lithium salt B as described in document WO 2018 / 104674. These impurities may optionally be present in said lithium salt A in a content less than or equal to that mentioned for said lithium salt B.

[0142] According to a preferred embodiment, said method also comprises a step b) of purifying said mixture of products obtained in step a) to isolate said lithium salt A. If step a) has been carried out in the presence of a solvent, the latter is preferably evaporated before carrying out step b). Said step b) comprises in particular a step of extracting said lithium salt A with an apolar organic solvent. Said apolar organic solvent is for example a C5-C 10 alkyl, C5-C 10 cycloalkyl, C6-C 10 aryl, C1-C3haloalkyl, diethyl ether, 1,4-dioxane, tetrahydrofuran or a mixture thereof. Preferably, said apolar organic solvent is n-hexane, pentane, heptane, cyclohexane, cyclopentane, benzene, toluene, xylene, cumene, CCI4, CHCI3, diethyl ether, 1,4-dioxane, tetrahydrofuran or a mixture thereof.

[0143] Said process according to the present invention makes it possible to obtain said lithium salt A with a very high purity. The mixture obtained in step b) and comprising said lithium salt and said apolar solvent is distilled to remove the apolar solvent and recovered said lithium salt A. The implementation of step b) makes it possible to obtain a composition comprising at least 95% by weight, preferably at least 98% by weight, in particular at least 99% by weight, more particularly at least 99.5% of lithium salt A based on the total weight of the composition. Said composition may comprise less than 1%, preferably less than 0.5% by weight of additional compounds selected from the group consisting of said compound C, said compound B and F-SiR 1 R 2 R 3 with R 1 , R 2 , R 3as defined in the present application. When said lithium salt B is LiN(S(O)2-F)2, said composition may comprise less than 1%, preferably less than 0.5% by weight of additional compounds selected from the group consisting of said compound C, said compound B, F-SiR 1 R 2 R 3 and Li N(S(O)2F)(S(O)2-OR) with R, R 1 , R 2 , R 3 as defined in this application.

[0144] Lithium salt of formula (Ilia), (111b), (111c), (llld), (111e), (lllf), (111g), (lllh), (llli), (lllj), (IVa), (IVb),

[0145] (IVc) or (IVd)

[0146] According to a second aspect of the present invention, a lithium salt is provided. According to a preferred embodiment, said lithium salt is of formula (IllA), (llIb), (llLc), (llId), (llI), (llLf), (llLg),

[0147] (lllh), (llli), (lllj), (IVa), (IVb), (IVc) or (IVd)

[0148]

[0149]

[0150] in which

[0151] X is a heteroatom selected from the group consisting of O, S and N(R 5 ) in which R 5 is H or C1-C 10 alkyl;

[0152] Y is a group selected from the group consisting of -C(R 6 )(R 7 )-, - C(R 6 )(R 7 )C(R 6 )(R 7 )SC(R 6 )(R 7 )- and -[(O) z (C(R 8 )(R 9 )-C(R 8 )(R 9 )O) m -C(R 8 )(R 9 )C(R 8 )(R 9 )]- with R 6 and R 7 independently selected for each carbon atom and for each Y unit from H or F; R 8 and R 9independently selected for each carbon atom and for each unit Y from H, F or CH3; m an integer from 1 to 50, advantageously from 1 to 40, preferably from 1 to 30, more preferably from 1 to 20, in particular from 1 to 10; z = 0 if X is O; n is an integer from 1 to 50, advantageously from 1 to 40, preferably from 1 to 30, more preferably from 1 to 20, in particular from 1 to 10;

[0153] A, B and V are independently selected from the group consisting of H, F, Cl, Br, I, C1-C 20 alkyl optionally substituted by one or more substituent(s) R", C2- C 20 alkenyl optionally substituted by one or more substituent(s) R", C3-C 20 cycloalkyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C4-C groups 20 cycloalkenyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C6-C groups20aryl optionally substituted with one or more substituent(s) R" or one or more C1-C5alkyl groups with R" selected from the group consisting of F, Cl, I, Br, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester, preferably F, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester;advantageously A, B and V are independently of each other selected from the group consisting of H, F, Cl, Br, I, C1-C15 alkyl optionally substituted by one or more substituent(s) R", C2-C15 alkenyl optionally substituted by one or more substituent(s) R", C3-C15 cycloalkyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl groups, C4-C15 cycloalkenyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl groups, C6-C1s aryl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl groups with R" selected from the group consisting of F, Cl, I, Br, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester, preferably F, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester; preferably A, B and;

[0154] V are independently selected from the group consisting of H, F, Cl, Br, I, C1-C 10 alkyl optionally substituted by one or more substituent(s) R", C2-C 10 alkenyl optionally substituted by one or more substituent(s) R", C3-C 10 cycloalkyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C4-C groups 10 cycloalkenyl optionally substituted by one or more substituent(s) R" or one or more C1-C5alkyl, C6-C groups 10aryl optionally substituted with one or more substituent(s) R" or one or more C1-C5alkyl groups with R" selected from the group consisting of F, Cl, I, Br, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester, preferably F, C1-C4ether, C1-C4ester, C1-C4thioether, C1-C4thioester; more preferably A, B and V are independently of each other selected from the group consisting of H, F, Cl, Br, I, C1-C 10 alkyl, C2-C 10 alkenyl, C3-C 10 cycloalkyl, C4-C 10 cycloalkenyl, C6-C 10 aryl, C1-C 10 perfluoroalkyl, C2-C 10 perfluoroalkenyl, C3-C 10 perfluorocycloalkyl, C4-C 10 perfluorocycloalkenyl, C6-C 10 perfluoroaryl; in particular A, B and

[0155] V are independently of each other selected from the group consisting of H, F, Cl, Br, I, C1-C5alkyl, C1-C5perfluoroalkyl, C6R 10 5 with R 10independently selected from H, F, C1-C5alkyl;

[0156] W is selected from O and S, preferably O;

[0157] R' is a substituent selected from the group consisting of F, C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy; preferably C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy.

[0158] Preferably, said lithium salt is of formula (Illa), (I II b), (I Ile), (IIId), (I Ile), (Il If), (Il Ig), (I llh), (llli), (lllj), (IVa), (IVb), (IVc) or (IVd) in which

[0159] X is a heteroatom selected from the group consisting of O, S and N(R 5 ) in which R 5 is H or C1-C 10 alkyl; preferably R 5 is H, CH3 or C2H5;

[0160] V is a group selected from the group consisting of -C(R 6 )(R 7 )-, - C(R 6 )(R 7 )C(R 6 )(R 7 )SC(R6 )(R 7 )- and -[(O) z (C(R 8 )(R 9 )-C(R 8 )(R 9 )O) m -C(R 8 )(R 9 )C(R 8 )(R 9 )]- with R 6 and R 7 independently selected for each carbon atom and for each Y unit from H or F; R 8 and R 9 independently selected for each carbon atom and for each unit Y from H, F or CH3; m an integer from 1 to 50, advantageously from 1 to 40, preferably from 1 to 30, more preferably from 1 to 20, in particular from 1 to 10; z = 0 if X is O; n is an integer from 1 to 50, advantageously from 1 to 40, preferably from 1 to 30, more preferably from 1 to 20, in particular from 1 to 10;

[0161] A and B are independently of each other selected from the group consisting of H, F, Cl, I, Br, CH3, C2H5, CF3, C2F5, phenyl; preferably A and B are the same and are selected from the group consisting of H, F, Cl, I, Br or A is H and B is selected from the group consisting of F, Cl, Br, I, CH3, C2H5, CF3, C2F5, phenyl;

[0162] V is selected from the group consisting of H, F, Cl, Br, I, C1-C5alkyl, C1-C5perfluoroalkyl, C6R 10 5 with R 10 independently selected from H, F, C1-C5alkyl;

[0163] W is selected from O and S, preferably O

[0164] R' is a substituent selected from the group consisting of F, C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy; preferably C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy.

[0165] In particular, said lithium salt is of formula (IIIa), (I II b), (I Ile), (Il Id), (Il le), (II If), (Il Ig), (I llh), (llli), (lllj), (IVa), (IVb), (IVc) or (IVd) in which

[0166] A and B are independently of each other selected from the group consisting of H, F, Cl, I, Br, CH3, C2H5, CF3, C2F5, phenyl; preferably A and B are the same and are selected from the group consisting of H, F, Cl, I, Br or A is H and B is selected from the group consisting of F, Cl, Br, I, CH3, C2H5, CF3, C2F5, phenyl;

[0167] V is selected from the group consisting of H, F, Cl, Br, I, C1-C5alkyl, C1-C5perfluoroalkyl, C6R 10 5 with R 10 independently selected from H, F, C1-C5alkyl;

[0168] W is O;

[0169] X is O;

[0170] Y is a group selected from the group consisting of CH2CH2, CH2CF2, CF2CF2, CH2CHF, CF2CH2, CHFCH2, and n is an integer from 1 to 25; or

[0171] Y is a grouping -[(C(R 8 )(R 9 )-C(R 8 )(R 9 )O) m -C(R 8 )(R 9 )C(R 8 )(R 9 )]- with R 8 and R 9 independently selected for each carbon atom and for each Y unit from H, F or CH3, m is an integer from 1 to 25 and n is 1;

[0172] R' is a substituent selected from the group consisting of F, C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy; preferably C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy. According to a preferred embodiment, said lithium salt is of formula (IIIa) in which

[0173] A and B are H,

[0174] Y is CH3OU H,

[0175] W is O,

[0176] X is O and

[0177] Y is a group selected from the group consisting of CH2CH2, CH2CF2, CF2CF2, CH2CHF, CF2CH2, CHFCH2, and n is an integer from 1 to 10; or

[0178] Y is a grouping -[(C(R 8 )(R 9 )-C(R 8 )(R 9 )O) m -C(R 8 )(R 9 )C(R 8 )(R 9 )]- with R 8 and R 9 independently selected for each carbon atom and for each Y unit from H, F or CH3, m is an integer from 1 to 25 and n is 1.

[0179] According to another aspect of the present invention, a polymer is provided. Said polymer comprises monomeric units derived from at least one of the lithium salts according to the present invention, i.e. according to any one of the formulae (IIIa), (IIIb), (IIIc), (IIId), (IIIe), (IIIf), (IIIg), (IIIh), (IIIi), (IIIj), (IVa), (IVb), (IVc) or (IVd). Said polymer may comprise monomeric units derived from one of the lithium salts according to the present invention or monomeric units derived from several of these salts. Said lithium salts may polymerize via their vinyl function.

[0180] According to a preferred embodiment, said polymer also comprises monomeric units derived from a monomer M1 of formula R 1 R 2 C=C(R 3 )C(O)R in which the substituents R 1 , R 2 and R 3are independently of each other selected from the group consisting of H and C1-C5alkyl; R is selected from the group consisting of - NHC(CH3)2CH2C(O)CH3OR -OR' with R' selected from the group consisting of H and C1-C 18 alkyl optionally substituted by one or more -OH group(s) or a five- or ten-membered heterocycle comprising at least one nitrogen atom in its ring chain. Said heterocycle may be saturated or unsaturated or aromatic. Said heterocycle may be monocyclic or bicyclic. Said heterocycle may be a pyrrole, pyrrolidine, pyridine, piperidine, pyrimidine, pyrazine, 1,4-dihydropyridine, indole, oxindole, isatin, quinoline, isoquinoline, quinazoline, imidazoline, pyrazolidine, 2-pyrrolidone, deltalactam, succinimide, 2-imidazolidinone, 4-imidazolidinone ring. Said heterocycle may be substituted by one or more C1-C5alkyl groups. As mentioned above, the C1-C 18alkyl is optionally substituted by said heterocycle. The latter may be linked to the alkyl chain by the nitrogen atom or any other atoms forming the heterocycle. Preferably the heterocycle is 2-pyrrolidone, delta-lactam, succinimide, 2-imidazolidinone, 4-imidazolidinone. Preferably, said monomer Ml is of formula R 1 R 2 C=C(R 3 )C(O)R in which the substituents R 1 , R 2 and R 3 are independently of each other selected from the group consisting of H and C1-C5alkyl; R is -OR' with R' selected from the group consisting of H, C1-C 18alkyl optionally substituted with one or more -OH group(s). According to a preferred embodiment, the substituent R' is selected from the group consisting of H, methyl, ethyl, propyl, n-butyl, isobutyl, t-butyl, n-dodecyl, amyl, isoamyl, hexyl, 2-ethylhexyl, lauryl, n-octyl, hydroxybutyl, hydroxypropyl, ethyl substituted with a ureido group, hydroxy ethyl, hydroxy propyl, hydroxy butyl.

[0181] In particular, said monomer Ml is of formula R 1 R 2 C=C(R 3 )C(O)R in which the substituents R 1 and R 2 are H; R 3 is H or CH3; R is -OR' with R' selected from the group consisting of H, methyl, ethyl, propyl, n-butyl, isobutyl, t-butyl, hydroxy propyl, hydroxy butyl, 2-pyrrolidone, deltalactam, succinimide, 2-imidazolidinone, 4-imidazolidinone.

[0182] Thus, said monomer Ml may be acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-dodecyl acrylate, amyl acrylate, isoamyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, diacetone acrylamide, lauryl acrylate, n-octyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, methyl acrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-dodecyl methacrylate, amyl methacrylate, isoamyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, n-octyl methacrylate, ureido methacrylate and mixtures thereof.Among these, alkyl acrylates with an alkyl group having 1 to 8 carbon atoms are preferred, and alkyl acrylates with an alkyl group having 1 to 5 carbon atoms are more preferable. These compounds can be used alone or as a mixture of two or more.

[0183] According to a preferred embodiment, said polymer also comprises monomeric units derived from a monomer M2 selected from the group consisting of vinylidene fluoride, vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoro(alkyl vinyl) ethers, perfluoro(1,3-dioxole), perfluoro(2,2-dimethyl-1,3-dioxole), the monomer of formula CF2=CFOCF2CF(CF3)OCF2CF2X in which X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H, the monomer of formula CF2=CFOCF2CF2SO2F, the monomer of formula F(CF2)nCH2OCF=CF2in which n is 1, 2, 3, 4 or 5, the monomer of formula R 1CH2OCF=CF2in which R 1 is hydrogen or F(CF2)m and m is 1, 2, 3 or 4, the monomer of formula R 2 OCF=CH2in which R 2 is F(CF2)p and p is 1, 2, 3 or 4, perfluorobutyl ethylene, trifluoropropene, tetrafluoropropene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropene, 2-trifluoromethyl- 3,3,3-trifluoro-l-propene. Preferably, said monomer M2 is selected from the group consisting of vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoro(alkyl vinyl) ethers, perfluoro(1,3-dioxole), perfluoro(2,2-dimethyl-1,3-dioxole), the monomer of formula CF2=CFOCF2CF(CF3)OCF2CF2X in which X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPC>3H, the monomer of formula CF2=CFOCF2CF2SO2F, the monomer of formula F(CF2)nCH2OCF=CF2in which n is 1, 2, 3, 4 or 5, the monomer of formula R 1CH2OCF=CF2in which R 1 is hydrogen or F(CF2)m and m is 1, 2, 3 or 4, the monomer of formula R 2 OCF=CH2in which R 2 is F(CF2)p and p is 1, 2, 3 or 4, tetrafluoropropene, chlorotrifluoropropene. In particular, said monomer M2 is selected from the group consisting of vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene, hexafluoropropylene, tetrafluoropropene, chlorotrifluoropropene.

[0184] Said polymer may also comprise monomeric units derived from a monomer M3 selected from the group consisting of fumaric acid, crotonic acid, itaconic acid and the like; vinyl ester compounds such as vinyl acetate, vinyl neodecanoate and the like; amide compounds such as acrylamide, methacrylamide, N-methylacrylamide, N-methylmethacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N-alkylacrylamide, N-alkylmethacrylamide, N,N-dialkylacrylamide, N,N-dialkylmethacrylamide, diacetone acrylamide and the like; N-dialkylaminoethyl acrylate, glycidyl acrylate, n-dodecyl acrylate, fluoroalkyl acrylate and the like; dialkylaminoethyl methacrylate, fluoroalkyl methacrylate, glycidyl methacrylate, ethylene glycol dimethacrylate and the like;maleic anhydride, and alkenyl glycidyl ether compounds such as allyl glycidyl ether and the like; conjugated dienes such as 1,3-butadiene, isoprene and the like; divinyl hydrocarbon compounds such as divinyl benzene and the like; and alkenyl cyanides such as acrylonitrile, methacrylonitrile and the like. These compounds may be used alone or as a mixture of two or more. Among these, the preferred ones are 1,3-butadiene, and acrylonitrile. The polymer as described in the present application can be used in many applications. Thus, said polymer can be used as a binder for an electrode (cathode or anode) or as a coating for a separator.;

[0185] Thus, according to another aspect, the present invention provides an electrode composition comprising said polymer according to the present invention, an active material and optionally a conductive agent.

[0186] In a preferred embodiment, the electrode composition has the following mass composition: a. 50% to 99.9% active material, preferably 50% to 99%, b. 25% to 0% conductive agent, preferably 25% to 0.5%, c. 25% to 0.05% of said binder according to the invention, preferably 25% to 0.5%, d. 0% to 5% of at least one additive selected from the group consisting of a plasticizer, an ionic liquid, a dispersing agent for conductive additive, and a flow aid; the sum of all these percentages being 100%.

[0187] The conductive agents in the electrode are composed of one or more materials that can improve conductivity. Some examples include carbon blacks such as acetylene black, Ketjen black; carbon fibers, such as carbon nanotube, carbon nanofiber, vapor-grown carbon fiber; metal powders such as SUS powder, and aluminum powder.

[0188] Active materials in electrode compositions are materials that are capable of storing and releasing lithium ions.

[0189] In a preferred embodiment, said electrode is a negative electrode. In particular, for a negative electrode, said active material is selected from the group consisting of a lithium alloy, lithium metal, a metal oxide, a carbon material such as graphite or hard carbon, silicon, silicone, a silicon alloy and Li4TiO12 - The shape of the negative electrode active material is not particularly limited but is preferably particulate.

[0190] In another preferred embodiment, said electrode is a positive electrode. Preferably, for a positive electrode, said active material is selected from the group consisting of LiCoO2, Li(Ni, Co, AI)C>2, Li(l+ x), NiaMnbCoc (x represents a real number of 0 or more, a = 0.8, 0.6, 0.5, or 1 / 3, b = 0.1, 0.2, 0.3, or 1 / 3, c = 0.1, 0.2, or 1 / 3), LiNiO2, LiMn2O4, LiCoMnO4, Li3NiMn3O3, Li3Fe2(PO4)3, Li3V2(PO4)3, a Li Mn spinel substituted by a different element having a composition represented by Lil+xMn2-x-yMyO4, M representing at least one metal selected from Al, Mg, Co, Fe, Ni, and Zn, x and y independently representing a real number between 0 and 2, lithium titanate LixTiOy - x and y independently representing a real number between 0 and 2, and a lithium metal phosphate having a composition represented by LiMPO4, M representing Fe, Mn, Co, or Ni.The shape of the positive electrode active material is not particularly limited but is preferably particulate. In addition, the surface of each of the materials described above can be coated. The coating material is not particularly limited as long as it has lithium ion conductivity and contains a material capable of being maintained as a coating layer on the surface of the active material. Examples of the coating material include LiNbO3, Li4Ti5O. 12 , and Li3PO4.

[0191] Said electrode composition can be deposited on at least one face of a current collector to form said electrode. This deposition can be carried out in the presence of an organic solvent, water, a mixture of both or by a solvent-free process. Said organic solvent can be selected from the group consisting of n-methylpyrrolidone (NMP), dimethylsulfoxide (DMSO), N,N-dimethylformamide (DMF), triethylphosphite (TEP), acetone, cyclopentanone, tetrahydrofuran, methyl ethylketone (MEK), methyl isobutyl ketone (MiBK), ethyl acetate (EA), butyl acetate (BA), ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), gammabutyrolactone and N-butylpyrrolidone; and mixtures thereof.

[0192] According to another aspect of the present invention, a Li-ion battery is provided. Preferably, the Li-ion battery comprises a positive electrode, a negative electrode and a separator, at least one electrode being an electrode according to the present invention.

[0193] According to another aspect of the present invention, said polymer according to the present invention can be used as a coating in a separator arranged between two electrodes. Said separator according to the present invention comprises a coating comprising, preferably consisting of, the polymer according to the present invention, optionally arranged on one or both faces of a porous support. In this case, the coating is used to coat the support of a separator, on at least one face, in the form of a monolayer or multilayers. There is no particular limitation in the choice of the support which is coated with the coating of the invention, as long as it is a porous substrate having pores. When it comprises several layers, the coating as described in the present invention is arranged on the external face of the support, that is to say on the face which will first be in contact with the electrolytic composition used in the battery.Advantageously, the application of the coating to the support is carried out by aqueous or solvent means. The porous substrate may take the form of a membrane or a fibrous fabric. When the porous substrate is fibrous, it may be a non-woven web forming a porous web, such as a web obtained by direct spinning or melt-blowing (of the "spunbond" or "melt-blown" type) or electro-spinning. Examples of porous substrates useful in the invention as a support include, but are not limited to: polyolefins, polyethylene terephthalate, polybutylene terephthalate, polyester, polyacetal, polyamide, polycarbonate, polyimide, polyetheretherketone, polyethersulfone, poly(phenylene oxide), poly(phenylene sulfide), polyethylene naphthalene or mixtures thereof. However, other heat-resistant engineering plastics may be used without particular limitation.Nonwoven materials made of natural and synthetic materials can also be used as the separator substrate. The porous substrate generally has a thickness of 1 to 50 μm, and are typically membranes obtained by extrusion and drawing (wet or dry process) or cast nonwovens. The porous substrate preferably has a porosity of between 5% and 95%. The average pore size (diameter) is preferably between 0.001 and 50 μm, more preferably between 0.01 and 10 μm. The support can also be aluminum or aluminum coated with a polymer layer. In addition to said composition, the separator coating can contain inorganic particles that serve to form micropores in the coating (the interstices between inorganic particles). The addition of inorganic particles can also contribute to heat resistance or improve wettability.In one embodiment, said coating comprises from 50 to 99 percent by weight of inorganic particles, based on the weight of the coating. These inorganic particles must be electrochemically stable (not subject to oxidation and / or reduction in the range of voltages used). In addition, the powdered inorganic materials preferably have a high ionic conductivity. Low density materials are preferred over higher density materials, since the weight of the produced battery can be reduced. The dielectric constant is preferably equal to or greater than 5. In one embodiment, said inorganic particles are selected from the group consisting of: BaTiO3, Pb(Zr,Ti)03, Pb 1-x LaxZryO3 (0 <x<l, 0<y<l), PBMg3Nb2 / 3)3,PbTiO3, hafnie (HfO (HfO2), SrTiO 3, SnO2, CeO2, MgO, NiO, CaO, ZnO, Y2O3, bohémite (y-AIO(OH)), AI2O3, TiO2, SiC, ZrO2, silicate de bore, BaSO4, nano-argiles, ou leurs mélanges.The separator coating may optionally comprise from 0 to 15% by weight based on the polymer, and preferably 0.1 to 10% by weight of additives, selected from thickeners, pH adjusting agents, anti-settling agents, surfactants, wetting agents, fillers, anti-foaming agents and fugitive or non-fugitive adhesion promoters. The fillers mentioned herein in the additives are different from the inorganic particles mentioned above.

[0194] According to another aspect of the present invention, a Li-ion battery is provided. Preferably, the Li-ion battery comprises a positive electrode, a negative electrode and said separator according to the present invention.

[0195] Examples

[0196] Example 1

[0197] In a 50 ml reactor, 1.06 g of LiFSI is dissolved in 20 ml of acetonitrile at room temperature (22 °C). To this solution, 1.5 ml of l,8-Diazabicyclo(5.4.0)undec-7-ene (2 eq. relative to LiFSI - pKa of 13.5 at 25 °C in water) is added and mixed for 5 minutes, followed by the addition of 2.54 ml of 2-(Trimethylsiloxy)ethyl methacrylate (2 eq. relative to LiFSI). The reaction mixture is stirred at room temperature for 24 h under ambient atmosphere. The acetonitrile is evaporated via a rotary evaporator at 30 °C and 1 mbar. The residue is mixed with petroleum ether until two phases are obtained. The upper phase containing lithium salt A and petroleum ether is separated and the petroleum ether is evaporated via a rotary evaporator at 30°C and 1 mbar. The recovered product is the lithium salt of formula (Ilia) with A and B = H, V = CH3, W = O, X = O and Y is CH2CH2; n = 1. The conversion of LiFSI is 100%.The purity of lithium salt is greater than 99%.

[0198] Example 2

[0199] Example 1 is reproduced with an amount of 0.17 ml of l,8-Diazabicyclo(5.4.0)undec-7-ene (0.2 eq. relative to LiFSI). The recovered product is the lithium salt of formula (Ilia) with A and B = H, V =CH3, W = O, X = O and Y is CH2CH2; n = 1. The conversion of LiFSI is 100%. The purity of the lithium salt is greater than 99%.

[0200] Example 1 is reproduced with an amount of 0.17 ml of l,8-Diazabicyclo(5.4.0)undec-7-ene

[0201] (0.2eq. relative to LiFSI), and 2 molar equivalents of p-(Trimethylsilyloxy) Styrene. The recovered product is the lithium salt of formula ( 11 Id ) with A and B = H, V = H, X = O. The conversion of LiFSI is 79%. The purity of the lithium salt is greater than 99%.

[0202] Example 4

[0203] Example 1 is reproduced with a quantity of 0.17 ml of l,8-Diazabicyclo(5.4.0)undec-7-ene (0.2 eq. relative to LiFSI), and 1 molar equivalent of p-(Trimethylsilyloxy) Styrene and 1 molar equivalent of 2-(Trimethoxysilyl)ethyl methacrylate. The recovered product is the lithium salt of formula (II Ig) with A and B = H, V = H, X = O, and A and B = H, V = CH3, W = O, X = O and Y is CH2CH2; n = 1. The conversion of LiFSI is 83%. e comparative 1

[0204] Example 1 is reproduced with 2.16 ml of triethylamine (2 eq. relative to LiFSI). Triethylamine has a pKa less than 11. The recovered product is the lithium salt of formula (Ilia) with A and B = H, V = CH3, W = O, X = O and Y is CH2CH2; n = 1. The conversion of LiFSI is 8%.

[0205] Example 5

[0206] To polymerize the monomers according to the present invention, the following procedure is followed. 3 g of water are introduced into a reactor equipped with a mixing and heating device. The temperature is set at 95°C. 3 g of a mixture of the compound of formula (IIIa) and methacrylic acid (10 / 90 in molar percentage) and 0.4 g of sodium persulfate in 7 g of water are introduced over a period of 2 hours. The temperature is maintained for 2 hours. The reactor is cooled to room temperature.

Claims

Demands 1. A process for preparing a lithium salt A comprising a step a) of contacting a lithium salt B comprising at least one -S(0)2-F group with a compound C of formula (I) RO-SiR 1 R 2 R 3 in the presence of a catalyst D to form a mixture of products comprising said lithium salt A comprising at least one -S(0)2-0R group; said catalyst D being a compound having a pKa greater than 11 measured at 25°C.

2. A process according to the preceding claim characterized in that the substituent R of said compound C comprises at least one carbon-carbon double bond.

3. A process according to any one of the preceding claims characterized in that said lithium salt B is of formula LiN(S(O)2-F)(S(O)2R') and said lithium salt A is of formula (IV) LiN(S(O)2-OR)(S(O)2R') in which R' is a substituent selected from the group consisting of F, C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy; preferably C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy.

4. A process according to any one of the preceding claims characterized in that said lithium salt B comprises two -S(0)2-F groups to form a lithium salt A comprising two -S(0)2-0R groups.

5. A process according to any one of the preceding claims characterized in that said lithium salt B is Li-N(S(O)2-F)2 and said lithium salt A is of formula (III) Li-N(S(O)2-OR)2.

6. A process according to any one of the preceding claims, characterized in that said compound C has the formula (I) RO-SiR 1 R 2 R 3 in which the R groups 1 , R 2 and R 3 are independently selected from the group consisting of H and C1-C 10 alkyl.

7. A process according to any one of the preceding claims, characterized in that said compound C has the formula (I) RO-SiR 1 R 2 R 3 in which the group R has the formula R 4 -X-(Y) n - in which R 4 is a radical comprising at least one double bond carbon-carbon; X is a heteroatom selected from the group consisting of O, S and N(R 5 ) in which R 5 is H or C1-C 10 alkyl; Y is a group selected from the group consisting of -C(R 6 (R 7 )-, -C(R 6 (R7 )C(R 6 (R 7 )SC(R 6 (R 7 )- and -[(O) Z (C(R 8 (R 9 )- C(R 8 (R 9 )O) m -C(R 8 (R 9 )C(R 8 (R 9 )]- with R 6 and R 7 independently selected for each carbon atom and for each unit Y from H or F, R 8 and R 9 independently selected for each carbon atom and for each unit Y from H, F, or CH3, m an integer from 1 to 50, z = 0 if X is O; n is an integer from 1 to 50. Method according to the preceding claim characterized in that the group R 4 is of formula (la), ( I b), (le) or (Id): in which A, B and V are independently selected from the group consisting of H, F, Cl, Br, I, C1-C 10 alkyl optionally substituted by one or more R substituent(s), C2-C 10optionally substituted alkenyl by one or more R substituent(s), C3-C 10 cycloalkyl optionally substituted by one or more R" substituent(s) or one or more C1-C5 alkyl, C4-C groups 10 cycloalkenyl optionally substituted by one or more R" substituent(s) or one or more C1-C5alkyl groups, C6-C12 aryl optionally substituted by one or more R" substituent(s) or one or more C1-C5alkyl groups; W is selected from O and S R" is selected from the group consisting of F, Cl, I, Br, C1-C4 ether, C1-C4 ester, C1-C4 thioether, C1-C4 thioester, preferably F, C1-C4 ether, C1-C4 ester, C1-C4 thioether, C1-C4 thioester. A process according to any one of the preceding claims, characterized in that said catalyst D is selected from the group consisting of N,N-Diisopropylethylamine, 1,8-Diazabicyclo(5.4.0)undec-7-ene, 6-(Dibutylamino)-1,8-Diazabicyclo[5.4.0]undec-7-ene, 1,8-Diazabicyclo[5.4.0]undec-7-ene linked to polystyrene, l,5,7-Triazabicyclo[4.4.0]dec-5-ene, 7-Methyl-l,5,7- triaza bicyclo[4.4.0]dec-5-ene, 1,1,3,3-Tetramethylguanidine, 2-tert-Butyl-l, 1,3,3- tetramethylguanidine, l,5,7-Triazabicyclo[4.4.0]dec-5-ene linked to polystyrene, 1,4-Diazabicyclo[2.2.2]octane, Quinuclidine, l,5-Diazabicyclo(4.3.0)non-5-ene, 2,6-Di-tert-butylpyridine, 2,8,9-Trimethyl-2,5,8,9-tetraza-l-phosphabicyclo[3.3.3]undecane, Cyclodiphosphazane, Lithium diisopropylamide, sodium diisopropylamide, potassium diisopropylamide, magnesium diisopropylamide, calcium diisopropylamide, rubidium diisopropylamide, lithium bis(trimethylsilyl)amide, sodium bis(trimethylsilyl)amide, potassium bis(trimethylsilyl)amide, magnesium bis(trimethylsilyl)amide, calcium bis(trimethylsilyl)amide, rubidium bis(trimethylsilyl)amide, lithium tetramethylpiperidide, sodium tetramethylpiperidide, potassium tetramethylpiperidide, magnesium tetramethylpiperidide, calcium tetramethylpiperidide, rubidium tetramethylpiperidide, [18-crown-6]-KHF2, KHF2, N,N'-diisopropylimidazonium, bifluoride, tetrabutylammonium. Process according to any one of the preceding claims, characterized in that it also comprises a step b) of purifying said lithium A salt; said step b) comprising the extraction of said lithium salt A by a non-polar organic solvent.A process according to any one of the preceding claims, characterized in that step a) is carried out at a temperature of 10 to 50°C. Lithium salt of formula (Illa), ( I II b), ( Il le), ( Il Id), ( Il le), ( 11 If), ( Il Ig), ( I II h), ( Il li), ( Il Ij), ( IVa ). (IVb), (IVc) or (IVd) AV wherein substituents A, B, V, and W are as defined in claim 8; substituents X and Y are as defined in claim 7; and n is as defined in claim 7 and R' is as defined in claim 3. Lithium salt according to the preceding claim of formula (Ilia), (lllb), (lllc), (11Id), (11le), (IlIf), (IlIg), (Illh), (Illi), (Illj), (IVa), (IVb), (IVc), or (IVd) wherein A and B are identical and are selected from the group consisting of H, F, Cl, Br and I; V is selected from the group consisting of H, F, Cl, Br, I, C1-C 10 alkyl optionally substituted by one or more R substituent(s), C2-C 10 optionally substituted alkenyl by one or more R substituent(s), C3-C 10 cycloalkyl optionally substituted by one or more R" substituent(s) or one or more C1-C5 alkyl, C4-C groups 10 cycloalkenyl optionally substituted by one or more R" substituent(s) or one or more C1-C5 alkyl, C6-C groups 12 aryl optionally substituted with one or more R" substituent(s) or one or more C1-C5 alkyl groups with R" is selected from the group consisting of F, Cl, I, Br, C1-C4 ether, C1-C4 ester, C1-C4 thioether, C1-C4 thioester; preferably V is selected from the group consisting of H, F, Cl, Br, I, C1-C5 alkyl, C1-C5 perfluoroalkyl, C6R 10 6 with R 10 independently selected from H, F, C1-C5alkyl; W is O; X is O; Y is a selected grouping from the group consisting of CH2CH2, CH2CF2, CF2CF2, CH2CHF, CF2CH2, CHFCH2, and n is an integer from 1 to 25; or Y is a grouping -[(C(R 8 (R 9 )-C(R 8 (R 9 )O) m -C(R 8 (R 9 )C(R 8 (R 9 )]- with R 8 and R 9 independently selected for each carbon atom and for each unit Y among H, F or CH3, m is an integer from 1 to 25 and n is 1; R' is a substituent selected from the group consisting of F, C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy; preferably C1-C4alkyl, C1-C4perfluoroalkyl, C1-C4alkoxy, C1-C4perfluoroalkoxy. Lithium salt according to any one of the preceding claims 12 or 13 of formula (Ilia), (lllb), (llllc), (llld), (llle), (lllf), (lllg), (lllh), (llli), (lllj), (IVa), (IVb), (IVc) or (IVd) wherein A and B are H, V is CH3, W is O, X is O and Y is a grouping selected from the group consisting of CH2CH2, CH2CF2, CF2CF2, CH2CHF, CF2CH2, CHFCH2, and n is an integer from 1 to 10; or Y is a grouping -[(C(R 8 (R 9 )-C(R 8 (R 9 )O) m -C(R 8 (R 9 )C(R 8 (R 9 )]- with R 8 and R 9 independently selected for each carbon atom and for each unit Y among H, F or CH3, m is an integer from 1 to 25 and n is 1; R' is a substituent selected from the group consisting of F, C1-C4 alkyl, C1-C4 perfluoroalkyl, C1-C4 alkoxy, C1-C4 perfluoroalkoxy. Lithium salt of formula (Ilia) according to any one of the preceding claims 12 to 14 wherein A and B are H, V is CH3, W is O, X is O and Y is a group selected from the group consisting of CH2CH2, CH2CF2, CF2CF2, CH2CHF, CF2CH2, CHFCH2, and n is an integer from 1 to 10; or Y is a grouping -[(C(R 8 (R 9 )-C(R 8 (R 9 )O) m -C(R 8 (R 9 )C(R 8 (R 9 )]- with R 8 and R 9independently selected for each carbon atom and for each unit Y from H, F or CH3, m is an integer from 1 to 25 and n is 1. Polymer comprising monomeric units from at least one lithium salt of formula (Ilia), (lllb), (llllc), (llld), (llle), (lllf), (llllg), (lllh), (llli), (lllj), (IVa), (IVb), (IVc) or (IVd) according to any one of claims 12 to 15. Polymer according to the preceding claim characterized in that it also comprises monomeric units derived from a monomer Ml of formula R 1 R 2 C=C(R 3 )C(O)R in which the substituents R 1 , R 2 and R 3 are independently selected from the group consisting of H and C1-C5 alkyl; R is selected from the group consisting of -NHC(CH3)2CH2C(O)CH3 or -OR' with R' selected from the group consisting of H and C1-C 18alkyl optionally substituted by one or more -OH group(s) or a five- or ten-membered heterocycle comprising at least one nitrogen atom in its cyclic chain. A polymer according to any one of the preceding claims 16 or 17, characterized in that it also comprises monomeric units derived from a monomer M2 selected from the group consisting of vinylidene fluoride, vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoro(alkyl vinyl) ethers, perfluoro(1,3-dioxole), perfluoro(2,2-dimethyl-1,3-dioxole), the monomer of formula CF2=CFOCF2CF2X in which X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H, the monomer of formula CF2=CFOCF2CF2SC>2F, the monomer of formula F(CF2)nCH2OCF=CF2 in which n is 1, 2, 3, 4 or 5, the monomer of formula R 1 CH2OCF=CF2 in which R 1is hydrogen or F(CF2)m and m is 1, 2, 3 or 4, the monomer of formula R 2 OCF=CH2 in which R 2 is F(CF2)p and p is 1, 2, 3 or 4, perfluorobutyl ethylene, trifluoropropene, tetrafluoropropene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropene, 2-trifluoromethyl-3,3,3-trifluoro-1-propene. Electrode binder or separator coating comprising said polymer according to any one of claims 16 to 18. Electrode or separator comprising said polymer according to any one of claims 16 to 18. Battery, preferably lithium-ion, comprising said electrode or separator according to the preceding claim.

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