FR3142042A1 - COMPOUND BASED ON (2-CYANOETHYL)PHOSPHONIUM SALT, ELECTROLYTE AND BATTERY COMPRISING IT - Google Patents

Abstract

The present invention relates to a (2-cyanoethyl)phosphonium salt compound, an electrolyte composition based on the (2-cyanoethyl)phosphonium salt compound and the battery comprising the same. It relates more particularly to an improved electrolyte composition for a lithium-ion or sodium-ion battery leading to improved capacity and cyclability. This electrolyte composition includes a lithium or sodium salt, an aprotic organic solvent, a (2-cyanoethyl)phosphonium salt compound.

Description

COMPOUND BASED ON (2-CYANOETHYL)PHOSPHONIUM SALT, ELECTROLYTE AND BATTERY COMPRISING IT

The present invention relates to a (2-cyanoethyl)phosphonium salt compound, an electrolyte composition based on the (2-cyanoethyl)phosphonium salt compound and the battery comprising the same. It relates more particularly to an improved electrolyte composition for a lithium-ion or sodium-ion battery leading to improved capacity and cyclability. This electrolyte composition includes a lithium or sodium salt, an aprotic organic solvent, a (2-cyanoethyl)phosphonium salt compound.

Field of the invention

An electrochemical battery is assembled from a cathode (positive electrode), an anode (negative electrode), a separator and an electrolyte. The operating principle is based on the reversible exchange of ions between the cathode and the anode. There is oxidation of the anode material and reduction of the electrolytic components and there is reduction of the cathode material and oxidation of the electrolytic components. Thanks to these redox reactions, a battery is charged by the conversion of electrical energy into chemical energy. The electrolyte plays an important role in the transport of ions between the cathode and the anode. Different compounds are used in electrolytes. Certain electrolyte compounds degrade and participate in the formation of the solid electrolyte interphase (SEI) and the formation of the cathode electrolyte interphase (CEI) to improve the properties and therefore the performance of the electrochemical cell, including cyclability, coulombic efficiency and capacity.

Current electrolyte technology uses compounds that do not allow sufficient improvement in the capacity and lifespan of the electrochemical cell.

The state of the art describes different compounds such as vinylene carbonate (commonly called VC), fluoroethylene carbonate (commonly called FEC), 1,3,6-hexanetricarbonitrile, acetonitrile, siloxanes, sulfates , sulphites, phosphates etc. which do not make it possible to achieve excellent cyclability, that is to say a long lifespan for the battery and excellent capacity while maintaining good conductivity of the electrolyte. They are not thermally stable and do not allow them to be soluble in variable proportions in the electrolyte solvent to adapt to the choice of electrode materials.

“The Role of Electrolyte Additives on the Interfacial Chemistry and Thermal Reactivity of Si-Anode-Based Li-Ion Battery”, ACS Applied Energy Materials 2019 2 (9), 6513-6527, describes classic compounds which, despite their beneficial characteristics, lead to persistent problems. For example, the presence of VC in the electrolyte can lead to too high a cell impedance. In another example, the presence of FEC in the electrolyte can lead to significant gas release at high temperature and therefore a risk of thermal runaway.

“Classical solid electrolyte interphase additives, such as vinylene carbonate and fluoroethylene carbonate, have limited potential for simultaneously achieving a long lifespan and fast chargeability in high-energy-density lithium-ion batteries (LIBs).” Park et al. 2021, describes the development of new electrolyte compounds for high energy density Li-ion batteries. This reference describes the disadvantages of conventional electrolyte compounds such as vinylene carbonate and fluoroethylene carbonate, they do not simultaneously achieve sufficient cycle life and sufficiently fast charging capacity in lithium batteries. -ion with high energy density.

Document DE102008021271 describes an electrolyte comprising a mono(2-cyanoethyl)phosphonium salt.

Document JP2018056013 also describes an electrolyte comprising a mono(2-cyanoethyl)phosphonium salt.

Compounds based on (2-cyanoethyl)phosphonium salt are particularly interesting because they are stable up to a temperature of 250°C; these compounds make it possible to choose one or the other of its members to adapt to the nature of the electrode as well as to modulate its solubility in the solvent of the electrolyte and not to be the cause of an increase in the internal resistance of the electrochemical cell during the SEI and/or IEC formation stage. However, mono(2-cyanoethyl)phosphonium compounds have the disadvantage of having to be in higher concentration to achieve the same effectiveness over time as bis(2-cyanoethyl)phosphonium compounds or tris(2- cyanoethyl)phosphonium. Indeed, to achieve the same efficiency, it is appropriate to multiply the concentration of mono(2-cyanoethyl)phosphonium whereas when the phosphonium molecule carries two or three 2-cyanoethyl chains, there is only a need for a higher concentration. weak molecule. This is important to avoid too high a viscosity and therefore avoid a reduction in the conductivity of the electrolyte. There is a need for a thermally stable electrolyte compound, soluble in varying proportions in the electrolyte solvent to meet the need for electrode selection and maintain excellent capacitance, excellent cyclability as well as good conductivity. and good electrochemical stability of the battery.

The inventors of the present invention have developed a new electrolyte compound for lithium-ion and sodium-ion batteries providing these systems with good cyclability and good capacity.

According to a first aspect of the invention, the electrolyte solvent thus comprises a (2-cyanoethyl)phosphonium salt of formula (I)

(I)

in which

-

R1 is independently chosen from an unsubstituted -CH ₂ -CH ₂ -CN chain, by a C1-C20 alkyl, a C3-C6 cycloalkyl, a C2-C20 alkenyl, a C5-C8 cycloalkenyl, an alkynyl in C2-C20, a vinylbenzyl group; in which the hydrogen atoms can be substituted by a fluorine, a -CF ₃ , an ether, an alkyl group, a perfluorinated alkyl group, a silyl group, a siloxy group, a sulfoxide group, a nitrile group, a thioether group or their combinations;

R2 is independently chosen from a C1-C20 alkyl group, a C3-C6 cycloalkyl, a C2-C20 alkenyl, a C5-C8 cycloalkenyl, a C2-C20 alkynyl, a vinylbenzyl group; in which the hydrogen atoms can be substituted by a fluorine, a -CF ₃ , an ether, an alkyl group, a perfluorinated alkyl group, a silyl group, a siloxy group, a sulfoxide group, a nitrile group, a thioether group or their combinations.

According to a second aspect, the invention also relates to an electrolyte composition comprising a lithium or sodium salt, an aprotic organic solvent, a (2-cyanoethyl)phosphonium salt compound as represented by formula (I).

According to a third aspect, the invention relates to a battery comprising an anode, a cathode and an electrolyte composition based on a (2-cyanoethyl)phosphonium salt compound as represented by formula (I).

Advantages of the invention

The invention proposes a new family of battery electrolyte compounds based on phosphonium salt. This compound provides an electrolyte that will be used in a battery with good cyclability and capacity. This leads to obtaining a high-performance and durable battery.

This new family of electrolyte compounds has several advantages.

Firstly, this family of compounds combines the properties of the nitrile present at least twice within the molecule and that of the phosphorus atom which allows better transport of Li+ ions. The molar ratio of the compound as a function of the number of nitrile functions carried by the compound is also improved. In fact, the more nitrile functions carried by the compound, the less it will be necessary to increase the mass of compound added; each compound has an optimum concentration for which the conductivity is maximum. The concentration will be lower and the conductivity will thus be improved.

The nitrile function adds polarity and specific reactivity. This also influences other physical properties such as dipole moment and dielectric constant. In addition, the nitrile function adds solvation properties to phosphonium cations intra- and intermolecularly, which improves the mobility of Li ⁺ ions.

Second, (2-cyanoethyl)phosphonium salt is thermally stable up to 250°C. This allows it on the one hand not to decompose into by-products which could be unfavorable to the good performance of the battery. On the other hand, the nitrile chemical function allows it to participate in the formation of the SEI and CEI in a sacrificial manner to preserve the chemical properties of the other electrolyte compounds in order to obtain a stable and effective SEI for the good performance of the battery. . This compound makes it possible to form an SEI at a temperature of 45°C.

Third, the compound is soluble in the electrolyte solvent in varying proportions to meet the need to adapt to the nature of the electrode materials. Indeed, this compound by its ionic nature is soluble in a proportion necessary for the type of electrode chosen.

This new family of compounds helps meet this need.

Fourth, a large number of molecules is accessible by replacing the R1 and R2 radicals, which makes it possible to have the molecule most suited to the electrochemical system, particularly with regard to the choice of electrodes and to achieve a high voltage.

Fifth, the synthesis process of this family of electrolyte compounds is industrializable.

The battery has a high capacity and long cyclability due to the nature of this molecule, namely the presence of the phosphorus atom and the presence of at least two - 2-cyanoethyl chains, this molecule being in monomeric form or dimer. Since the dimer is a homodimer, the nature of the chemical substitution remaining the same, the monomer and the dimer will have similar chemical properties.

The compounds bis(2-cyanoethyl)phosphonium and tris(2-cyanoethyl)phosphonium are the preferred compounds.

Detailed description of the invention

A first object of the invention relates to an electrolyte compound based on (2-cyanoethyl)phosphonium salt for high capacity and long cyclability battery as represented by formula (I)

(I)

in which

-

R1 is independently selected from the group consisting of an unsubstituted -CH ₂ -CH ₂ -CN chain, a C1-C20 alkyl, a C3-C6 cycloalkyl, a C2-C20 alkenyl, a C5-C8 cycloalkenyl , a C2-C20 alkynyl, a vinylbenzyl group; in which the hydrogen atoms can be substituted by a fluorine, a -CF ₃ , an ether, an alkyl group, a fluorinated alkyl group, a silyl group, a siloxy group, a sulfoxide group, a nitrile group, a thioether group or their combinations.

R2 is independently chosen from the group consisting of a C1-C20 alkyl group, a C3-C6 cycloalkyl, a C2-C20 alkenyl, a C5-C8 cycloalkenyl, a C2-C20 alkynyl, a vinylbenzyl group; in which the hydrogen atoms can be substituted by a fluorine, a -CF ₃ , an ether, an alkyl group, a perfluorinated alkyl group, a silyl group, a siloxy group, a sulfoxide group, a nitrile group, a thioether group or their combinations.

The hydrogen atoms can therefore be partly substituted as long as the molecule is stable.

The term "alkyl" designates a saturated aliphatic radical, linear or branched, having the indicated number of carbon atoms. The alkyl moiety may be straight or branched chain

The term “alkenyl” designates an alkyl group, as defined above, comprising at least one C=C double bond.

The term “alkynyl” designates an alkyl group, as defined above, comprising at least one C≡C triple bond.

The term "cycloalkyl" designates a set of saturated or partially unsaturated, monocyclic, bicyclic, bridged polycyclic or spiro rings. Monocyclic rings include, for example, cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl rings.

In a particularly preferred embodiment, the (2-cyanoethyl)phosphonium salt comprises three 2-cyanoethyl chains and corresponds to formula (II) in which

-

R1 is independently chosen from a C1-C20 alkyl, a C3-C6 cycloalkyl, a C2-C20 alkenyl, a C5-C8 cycloalkenyl, a C2-C20 alkynyl, a vinylbenzyl group; in which the hydrogen atoms can be substituted by a fluorine, a -CF ₃ , an ether, an alkyl group, a perfluorinated alkyl group, a silyl group, a siloxy group, a sulfoxide group, a nitrile group, a thioether group or their combinations.

R2 is independently chosen from a C1-C20 alkyl group, a C3-C6 cycloalkyl, a C2-C20 alkenyl, a C5-C8 cycloalkenyl, a C2-C20 alkynyl, a vinylbenzyl group; in which the hydrogen atoms can be substituted by a fluorine, a -CF ₃ , an ether, an alkyl group, a perfluorinated alkyl group, a silyl group, a siloxy group, a sulfoxide group, a nitrile group, a thioether group or their combinations.

In a more particularly preferred embodiment, R1 is a C1-C10 alkyl in which the hydrogen atoms can be substituted by a fluorine, a -CF ₃ , an ether, an alkyl group, a perfluorinated alkyl group, a group silyl, a siloxy group, a nitrile group, a sulfoxide group, a thioether group or combinations thereof;

Even more preferably, R1 is chosen from a methyl or a C1-C4 alkyl in which the hydrogen atoms can be substituted by a fluorine, a -CF ₃ , an ether, an alkyl group, a perfluorinated alkyl group, a silyl group, a siloxy group, a nitrile group, a sulfoxide group, a thioether group or combinations thereof; and R2 is a C1-C10 alkyl in which the hydrogen atoms can be substituted by a fluorine, a -CF ₃ , an ether, an alkyl group, a perfluorinated alkyl group, a silyl group, a siloxy group, a group sulfoxide, a nitrile group, a thioether group or combinations thereof; and more preferably R2 is a C1-C4 alkyl in which the hydrogen atoms can be substituted by a fluorine, a -CF ₃ , an ether, an alkyl group, a perfluorinated alkyl group, a silyl group, a group siloxy, a nitrile group, a sulfoxide group, a thioether group or their combinations and most preferably from a methyl, an ethyl, a propyl, an iso-butyl, an n-butyl, or an allyl.

In a preferred embodiment, , fluorosulfonyl(trifluoromethanesulfonyl)imide, bis(oxalato)borate, difluorobis(oxalato)borate, acetate., N-ethyl-N-methyl-functionalized sulfonimide, (difluoromethanesulfonyl)(trifluoromethanesulfonyl)imide, (methanesulfonyl)(trifluoromethanesulfonyl)imide, ( difluoromethanesulfonyl)(fluoromethanesulfonyl)imide, (methanesulfonyl)(fluoromethanesulfonyl)imide.

In an even more preferred embodiment, X- is chosen from FSI or TFSI.

The preferred ^embodiments regarding the choice of the anion

In a preferred embodiment, the (2-cyanoethyl)phosphonium salt comprises three 2-cyanoethyl chains and corresponds to formula (II)

(II)

in which

-

R2 is independently chosen from a C1-C20 alkyl group, a C3-C6 cycloalkyl, a C2-C20 alkenyl, a C5-C8 cycloalkenyl, a C2-C20 alkynyl, a vinylbenzyl group; in which the hydrogen atoms can be substituted by a fluorine, a -CF ₃ , an ether, an alkyl group, a perfluorinated alkyl, a silyl group, a siloxy group, a sulfoxide group, a nitrile group, a thioether group or their combinations.

In a preferred embodiment, R2 is a C1-C10 alkyl in which the hydrogen atoms can be substituted by a fluorine, a -CF ₃ , an ether, an alkyl group, a perfluorinated alkyl group, a silyl group, a siloxy, a sulfoxide group, a nitrile group, a thioether group or combinations thereof; more preferably R2 is chosen from a C1-C4 alkyl in which the hydrogen atoms can be substituted by a fluorine, a -CF ₃ , an ether, an alkyl group, a perfluorinated alkyl group, a silyl group, a siloxy group, a sulfoxide group, a nitrile group, a thioether group or combinations thereof; very preferably R2 is chosen from methyl, ethyl, propyl, iso-butyl, n-butyl or allyl.

In a preferred embodiment, , fluorosulfonyl(trifluoromethanesulfonyl)imide, bis(oxalato)borate, difluorobis(oxalato)borate, acetate. N -ethyl- N -methyl-functionalized sulfonimide, (difluoromethanesulfonyl)(trifluoromethanesulfonyl)imide, (methanesulfonyl)(trifluoromethanesulfonyl)imide, (difluoromethanesulfonyl)(fluoromethanesulfonyl)imide, (methanesulfonyl)(fluoromethanesulfonyl)imide.

In an even more preferred embodiment, X- is chosen from FSI or TFSI.

The preferred ^embodiments regarding the choice of the anion

In a particular embodiment the (2-cyanoethyl)phosphonium salt is in the form of a phosphonium salt dimer as represented by formula (III),

(III)

in which

Z is chosen from C1-C20 alkyl di-radicals of type –(CH ₂ ) _n – which may comprise one or more ethers or which may comprise one or more sequences of type –CH ₂ –Y–CH ₂ – with Y=S or SO or SO2; preferably the alkyl di-radical is an ethyl, propyl, butyl or pentyl di-radical.

-

R2 is independently chosen from the group consisting of an unsubstituted -CH2-CH2-CN chain, a C1-C20 alkyl, a C3-C6 cycloalkyl, a C2-C20 alkenyl, a C5-C8 cycloalkenyl, a C2-C20 alkynyl, a vinylbenzyl group, a vinylbenzyl group; in which the hydrogen atoms can be substituted by a fluorine, a -CF3, an ether, an alkyl group, a perfluorinated alkyl group, a silyl group, a siloxy group, a sulfoxide group, a nitrile group, a thioether group or their combinations.

In a more particularly preferred embodiment, R2 is a C1-C10 alkyl in which the hydrogen atoms can be substituted by a fluorine, a -CF ₃ , an ether, an alkyl group, a perfluorinated alkyl group, a group silyl, a siloxy group, a sulfoxide group, a thioether group or combinations thereof.

Even more preferably, R2 is chosen from a methyl or a C1-C4 alkyl in which the hydrogen atoms can be substituted by a fluorine, a -CF ₃ , an ether, an alkyl group, a perfluorinated alkyl group, a silyl group, a siloxy group, a sulfoxide group, a thioether group or combinations thereof.

In a preferred embodiment, , fluorosulfonyl(trifluoromethanesulfonyl)imide, bis(oxalato)borate, difluorobis(oxalato)borate, acetate. N -ethyl- N -methyl-functionalized sulfonimide, (difluoromethanesulfonyl)(trifluoromethanesulfonyl)imide, (methanesulfonyl)(trifluoromethanesulfonyl)imide, (difluoromethanesulfonyl)(fluoromethanesulfonyl)imide, (methanesulfonyl)(fluoromethanesulfonyl)imide.

In an even more preferred embodiment, X- is chosen from FSI or TFSI.

The preferred embodiments regarding the choice of the anion X ^- explained above can be combined with the preferred embodiments regarding the choice of the R2 groups explained previously.

A second object of the invention is an electrolyte composition comprising a lithium or sodium salt, an aprotic organic solvent and a (2-cyanoethyl)phosphonium salt compound as described above.

According to a preferred embodiment, the aprotic organic solvent is chosen from an ionic liquid, a carbonate, a glyme, an alkyl sulfonamide or a mixture thereof.

In a preferred embodiment, the solvent is an ionic liquid.

As used in the present invention, "ionic liquid" means a salt molten at a temperature below 100°C.

When the solvent is an ionic liquid, it comprises (i) a cation chosen from an imidazolium, or a pyrrolidinium, a morpholinium, a pyridinium, a piperidinium, a phosphonium, an ammonium and (ii) an anion chosen from hexafluorophosphate ( PF6-), tetrafluoroborate (BF4-), bis(trifluoromethanesulfonyl)imide (TFSI), bis(fluorosulfonyl)imide (FSI), dicyanamide (DCA), 4,5-dicyano-2-(trifluoromethyl)imidazolide (TDI), fluorosulfonyl-(trifluoromethanesulfonyl)imide (FTFSI), (difluoromethanesulfonyl)(trifluoromethanesulfonyl)imide (DFTFSI), bis(oxalato)borate (BOB), difluoro(oxalato)borate (DFOB).

In a preferred embodiment, the ionic liquids chosen are of high quality [purity 99.9%; H2O ≤ 5 ppm; halides ≤ 1 ppm; lithium, sodium and potassium ≤ 10 ppm; organic nitrogen compounds ≤ 10 ppm; color test 20-10 Hazen].

In a preferred embodiment, the electrolyte composition comprises at least 30% ionic liquid, in particular at least 50% ionic liquid and preferably at least 70% ionic liquid.

A third object of the invention is a battery comprising a cathode, an anode, a separator and the electrolyte comprising a (2-cyanoethyl)phosphonium salt compound as described above.

In a particular embodiment, the battery according to the invention can provide an energy density greater than 350 Wh/kg when the electrolyte is composed of ionic liquid and the (2-cyanoethyl)phosphonium salt compound. Indeed, the compound is compatible with the performances of ionic liquids such as non-flammability, high voltage and use with high temperatures.

1. Pour une batterie Lithium-ion : un composé intercalant du lithium, choisi parmi le phosphate de lithium-fer, (LiFePO4), l’oxyde de lithium-nickel-manganèse-cobalt, (LiNixMnyCozO2), l’oxyde de lithium-nickel-manganèse-cobalt dopé, (LiNixMnyCozO2), l’oxyde de lithium-cobalt (LiCoO2), l’oxyde de lithium-cobalt dopé, l’oxyde de lithium-nickel (LiNiO2), l’oxyde de lithium-nickel dopé, l’oxyde de lithium-manganèse (LiMn2O4), l’oxyde de lithium-manganèse dopé, NCA, l’oxyde de lithium-vanadium, l’oxyde de lithium-vanadium dopé, des oxydes de lithium et de métaux mixtes, Lithium Manganèse Nickel Oxyde (LMNO), des oxydes de lithium et de métaux de transition mixtes, des oxydes de lithium et de métaux de transition mixtes dopés (NCA, LMNX,), le phosphate de lithium-vanadium, le phosphate de lithium-manganèse, le phosphate de lithium-cobalt, les phosphates de lithium et de métaux mixtes, les sulfures métalliques et leurs combinaisons.
2. Pour une batterie Sodium-ion : un oxyde métallique tel que VO2, V2O5, H2V3O8, b- MnO2 ;

The active material for the cathode is chosen from:

1. For a Lithium-ion battery: a lithium intercalating compound, chosen from lithium iron phosphate (LiFePO4), lithium-nickel-manganese-cobalt oxide (LiNixMnyCozO2), lithium-nickel oxide doped manganese-cobalt, (LiNixMnyCozO2), lithium-cobalt oxide (LiCoO2), doped lithium-cobalt oxide, lithium-nickel oxide (LiNiO2), doped lithium-nickel oxide, l lithium manganese oxide (LiMn2O4), doped lithium manganese oxide, NCA, lithium vanadium oxide, doped lithium vanadium oxide, lithium and mixed metal oxides, Lithium Manganese Nickel Oxide (LMNO), mixed lithium and transition metal oxides, doped lithium and mixed transition metal oxides (NCA, LMNX,), lithium vanadium phosphate, lithium manganese phosphate, phosphate lithium-cobalt, lithium and mixed metal phosphates, metal sulphides and combinations thereof.
2. For a Sodium-ion battery: a metal oxide such as VO2, V2O5, H2V3O8, b-MnO2;

• des oxydes tunnel 1D tels que Na0.44MnO2,Na0.66[Mn0.66Ti0.34]O2, Na0.61[Mn0.27Fe0.34Ti0.39]O2 ;
• des fluorures tels que FeO0.7F1.3 et NaFeF3 ;
• des sulfates tels que Na2Fe2(SO4)3 et Eldfellite NaFe(SO4)2 ;
• des phosphates NaFePO4 et FePO4 ; Na3V2(PO4)3, Na3V2(PO4)3, Na3V2(PO4)3@C@rGO, Na3V2(PO4)3/C, NaVOPO4 ;
• des pyrophosphates tels que Na2CoP2O7, Na2FeP2O7 et Na3.12Fe2.44(P2O7)2 ;

layered NaMOX such as Na0.71CoO2, Na0.7MnO2, b-NaMnO2, Na1.1V3O7.9, Na2RuO3, Na2/3[Ni1/3Mn2/3]O2, Na0.67Co0.5Mn0.5O2, Na0.66Li0. 18Mn0.71Ni0.21Co0.08O2+x;

• 1D tunnel oxides such as Na0.44MnO2,Na0.66[Mn0.66Ti0.34]O2, Na0.61[Mn0.27Fe0.34Ti0.39]O2;
• fluorides such as FeO0.7F1.3 and NaFeF3;
• sulfates such as Na2Fe2(SO4)3 and Eldfellite NaFe(SO4)2;
• NaFePO4 and FePO4 phosphates; Na3V2(PO4)3, Na3V2(PO4)3, Na3V2(PO4)3@C@rGO, Na3V2(PO4)3/C, NaVOPO4;
• pyrophosphates such as Na2CoP2O7, Na2FeP2O7 and Na3.12Fe2.44(P2O7)2;

• des phosphates mixtes tels que Na7V4(P2O7)4(PO4), Na3MnPO4CO3 ;
• des hexacyanométalates tels que MnHCMn PBAs, Na1.32Mn[Fe(CN)6]0.83.3.5H2O, NaxCo[Fe(CN)6]0.90·2.9H2O ;
• des cathodes sans métal critique telles que Na2C6O6, Na6C6O6, SSDC, C6Cl4O2/CMK, PTCDA-PI, les poly(anthraquinonyl imide)s et le graphite fonctionnalisé ;
• les analogues de blanc de Prusse ;
• les analogues du bleu de Prusse.

fluorophosphates such as NaVPO4F, Na3V2(PO4)2F3, Na3V2O2(PO4)2F@RuO2, Na3(VO1-xPO4)2F1+2x, Na3.5V2(PO4)2F3;

• mixed phosphates such as Na7V4(P2O7)4(PO4), Na3MnPO4CO3;
• hexcyanometalates such as MnHCMn PBAs, Na1.32Mn[Fe(CN)6]0.83.3.5H2O, NaxCo[Fe(CN)6]0.90·2.9H2O;
• critical metal-free cathodes such as Na2C6O6, Na6C6O6, SSDC, C6Cl4O2/CMK, PTCDA-PI, poly(anthraquinonyl imide)s and functionalized graphite;
• analogues of Prussian white;
• analogues of Prussian blue.

1. Pour une batterie Lithium-ion :

• un oxyde composite de titane contenant du lithium (LTO) ;
• mélange d’oxydes de niobium (XNO)
• des métaux (Me) tels que Si, Sn, Li, Zn, Mg, Cd, Ce, Ni et Fe ou des alliages de ceux-ci ;
• le graphite, le graphène, y compris les particules de graphite naturel, de graphite artificiel, de microbilles de méso-carbone (MCMB) et de carbone (y compris le carbone mou, le carbone dur, les nanofibres de carbone et les nanotubes de carbone) ;
• le silicium (Si), des composites silicium/graphite, des combinaisons de silicium de germanium (Ge), l’étain (Sn), le plomb (Pb), l’antimoine (Sb), le bismuth (Bi), le zinc (Zn), l’aluminium (Al), le nickel (Ni), le cobalt (Co), le manganèse (Mn), le titane (Ti), le fer (Fe) et le cadmium (Cd) ;
• des alliages ou composés intermétalliques de Si, Ge, Sn, Pb, Sb, Bi, Zn, Al ou Cd avec d’autres éléments, lesdits alliages ou composés étant stœchiométriques ou non stœchiométriques ;
• des oxydes, carbures, nitrures, sulfures, phosphures, séléniures et tellurures de Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Fe, Ni, Co, Ti, Mn ou Cd, et leurs mélanges ou composites ;
• des oxydes (MeOx) des métaux (Me) ;
• des composites des métaux (Me) avec du carbone ;
• des matériaux MXene, [M_xC où X = 2,3,4).

1. Pour une batterie Sodium-ion : des matériaux à base d’oxydes, de sulfures, de séléniures, de phosphures et de MOF et des matériaux à base de carbone ;les matériaux à base de carbone comprennent le graphite expansé, le graphite expansé dopé N, le noir de carbone, le carbone amorphe, les microsphères de carbone, le carbone dur, le carbone mou méso-puissant, les nanotubes de carbone, les nanofeuillets de graphène, les CNT dopés à l’azote, la mousse de graphène dopée N, les nanofibres poreuses dopées N, le carbone microporeux et le carbone poreux en forme de cube ; les oxydes comprennent les nanofleurs de MnO2, les nanofeuillets de NiO, le SnO poreux, les nanotubes de SnO2 poreux, le Fe3O4–C 3D poreux, le CuO-RGO poreux, les MnO-CNT dopés à l’azote ultrapetits, les micro-fleurs de CuS, SnS2-RGO, Co3S4-PANI, ZnS-RGO, NiS-RGO, Co3S4-PANI, MoS2–C, les nanofeuillets de WS2-carbone conducteur dopé à l’azote, les nanotiges de Sb3Se3-RGO, le MoSe2-fibre de carbone, les nanostructures de Sn4P3 à coquilles multiples, les nanosphères de Sn4P3–C, Se4P4, les nanoparticules de CoP, les matrices de nanotiges FeP sur du tissu de carbone, MoP-C, CUP2-C, le graphène NiO/Ni creux, le CoSe/C structuré en coquille-jaune dopé à l’azote ; le métal de Na.

The active material for the anode is chosen from:

1. For a Lithium-ion battery:

• a lithium-containing composite titanium oxide (LTO);
• mixture of niobium oxides (XNO)
• metals (Me) such as Si, Sn, Li, Zn, Mg, Cd, Ce, Ni and Fe or alloys thereof;
• graphite, graphene, including particles of natural graphite, artificial graphite, meso-carbon microbeads (MCMB) and carbon (including soft carbon, hard carbon, carbon nanofibers and carbon nanotubes ) ;
• silicon (Si), silicon/graphite composites, silicon combinations of germanium (Ge), tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), zinc (Zn), aluminum (Al), nickel (Ni), cobalt (Co), manganese (Mn), titanium (Ti), iron (Fe) and cadmium (Cd);
• alloys or intermetallic compounds of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al or Cd with other elements, said alloys or compounds being stoichiometric or non-stoichiometric;
• oxides, carbides, nitrides, sulphides, phosphides, selenides and tellurides of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Fe, Ni, Co, Ti, Mn or Cd, and their mixtures or composites;
• oxides (MeOx) of metals (Me);
• composites of metals (Me) with carbon;
• MXene materials, [M _x C where X = 2,3,4).

1. For a Sodium-ion battery: materials based on oxides, sulfides, selenides, phosphides and MOFs and carbon-based materials; carbon-based materials include expanded graphite, N-doped expanded graphite , carbon black, amorphous carbon, carbon microspheres, hard carbon, meso-strong soft carbon, carbon nanotubes, graphene nanosheets, nitrogen-doped CNTs, N-doped graphene foam , N-doped porous nanofibers, microporous carbon and cube-shaped porous carbon; oxides include MnO2 nanoflowers, NiO nanosheets, porous SnO, porous SnO2 nanotubes, porous 3D Fe3O4–C, porous CuO-RGO, ultrasmall nitrogen-doped MnO-CNTs, micro- CuS flowers, SnS2-RGO, Co3S4-PANI, ZnS-RGO, NiS-RGO, Co3S4-PANI, MoS2–C, nitrogen-doped conductive WS2-carbon nanosheets, Sb3Se3-RGO nanorods, MoSe2 -carbon fiber, multi-shell Sn4P3 nanostructures, Sn4P3–C nanospheres, Se4P4, CoP nanoparticles, FeP nanorod arrays on carbon fabric, MoP-C, CUP2-C, graphene NiO/ Neither hollow, yellow-shell structured CoSe/C doped with nitrogen; the metal of Na.

In a preferred embodiment, for Lithium-ion and Sodium-ion batteries, when the cathode is made of Lithium Manganese Nickel Oxide (LMNO) then the anode is made of graphite or Lithium Titanate (LTO); when the cathode is Nickel Manganese Cobalt 532 (NMC532) then the anode is graphite; when the cathode is Nickel Manganese Cobalt 622 (NMC622) then the anode is graphite; when the cathode is made of Nickel Manganese Cobalt 811 (NMC811) then the anode is made of graphite when the cathode is made of Lithium Iron Phosphate (LFP) then the anode is made of graphite; when the cathode is made of Lithium Iron Phosphate (LFP) then the anode is made of Lithium Titanate (LTO).

The separators can be made up:

- a microporous polymer membrane which is a semi-crystalline polyolefin such as polyethylene (PE), polypropylene (PP), high density polyethylene (HDPE), PE-PP, PS-PP, polyethylene terephthalate blends- polypropylene (PET-PP), poly(vinylidene fluoride) (PVDF), polyacrylonitrile (PAN); polyoxymethylene, poly(4-methyl-1-pentene); of non-woven fabric carpet such as cellulose, polyolefin, polyamide, polytetrafluoroethylene (PTFE), poly(vinylidene fluoride-co-hexafluoropropylene (PVDF-HFP), polyvinyl chloride (PVC), polyester. Other types of polymers are polyolefin-based materials and their blends such as polyethylene-polypropylene Graft polymers such as siloxane-grafted polyethylene separators, poly(methylmethacrylate)-grafted microporous separators. polyvinylidene fluoride (PVDF). Polytriphenylamine (PTPAn) modified separator. Polymer electrolytes such as ionic polymer electrolytes.

Examples of such ionic polymers are compounds formed from, for example, poly(diallyldimethylammonium) with an anion chosen from hexafluorophosphate (PF6-), tetrafluoroborate (BF4-), bis(trifluoromethanesulfonyl)imide (TFSI), bis(fluorosulfonyl)imide (FSI), dicyanamide (DCA), 4,5-dicyano-2-(trifluoromethyl)imidazolide (TDI), fluorosulfonyl-(trifluoromethanesulfonyl)imide (FTFSI) and (difluoromethanesulfonyl) (trifluoromethanesulfonyl) imide (DFTFSI), bis(oxalato)borate (BOB), difluoro(oxalato)borate (DFOB).

- Ionic liquid polymers with, in addition, ionic liquids (or without), mixed polymer/copolymer electrolytes of polyethylene oxide (PEO), polyvinylpyrrolidone, polyethylene oxide, polyacrylonitrile, polyethylene glycols, glymes, fluoropolymers with any other combination polymer electrolytes and ionic liquids or a combination of ionic liquids and polymer ionic liquid.

- Polymerizable ionic liquid;

- Inorganic composite separator such as metal oxide powders (TiO2, ZrO2, LiAlO2, Al2O3, MgO, CaCO3) in a polymer matrix (PVDF-HFP, PTFE), AlO (OH)/polyvinyl alcohol (PVA) on PET ; ceramic separators such as alumina or ceramic particles mixed with polymers or a combination of polymers and/or ionic liquids; surface-coated polymer such as a gel-like polymer film (PEO, PVDF-HFP) on microporous membranes; impregnation of a gel polymer electrolyte such as an ionic liquid-based electrolyte in microporous membranes; fiberglass; conductive glass separators. The separators may also include solid-state electrolytes such as solid ceramic electrolytes and solid polymer electrolytes.

In a preferred embodiment, the battery comprises an electrolyte composition comprising an ionic liquid solvent and the (2-cyanoethyl)phosphonium salt compound described in formulas (I), (II) or (III) as well as a cathode made of Lithium Manganese Nickel Oxide (LMNO) material.

In a particular embodiment, the battery comprises a cathode, an electrolyte as described above and a separator.

In a particular embodiment, the battery comprises a separator and an electrolyte which are identical. This is particularly the case when the electrolyte is solid because it also plays the role of separator.

BRIEF DESCRIPTION OF THE FIGURES

: Graph showing the charge/discharge profiles of the cell (LMNO//Graphite) at charge and discharge rates of 0.1 C and the 10th, 100th, 250th and 450th cycles at 0.5 C from 2 V to 5 V versus to Li+/Li for the electrolyte 1 M LiFSI in PYR13FSI + 0.063 mol/kg of Tris(2-cyanoethyl)methylphosphonium bis(fluorosulfonyl)imide (P1(2CN)3FSI) at 20 °C.

: Graph showing the charge/discharge profiles of the cell (LMNO//Graphite) at charge and discharge rates of 0.1 C and the 10th and 47th cycles at 0.5 C from 2 V to 5 V versus Li+/Li for the 1 M LiFSI electrolyte in PYR13FSI at 20 °C.

: Graph showing discharge capacities and coulombic efficiencies versus number of cycles for whole cells (LMNO//Graphite) with and without compound Tris(2-cyanoethyl)methylphosphonium bis(fluorosulfonyl)imide (P1(2CN)3FSI) at a charge and discharge rate of 0.5 C from 2 V to 5 V compared to Li+/Li at 20 °C.

: Graph showing the charge/discharge profiles of the cell (LMNO//Graphite) at charge and discharge rates of 0.1 C and the 10th, 50th, 150th and 274th cycles at 0.5 C from 2 V to 5 V versus to Li+/Li for the 1M LiFSI electrolyte in PYR13FSI + 0.063 mol/kg of Bis(2-cyanoethyl)butylmethylphosphonium bis(fluorosulfonyl)imide (P14(2CN)2FSI) at 20 °C.

: Graph showing the charge/discharge profiles of the cell (LMNO//Graphite) at charge and discharge rates of 0.1 C and the 10th, 50th, 150th and 247th cycles at 0.5 C from 2 V to 5 V versus to Li+/Li for the 1M LiFSI electrolyte in PYR13FSI at 20 °C.

: Graph showing discharge capacities and coulombic efficiencies versus number of cycles for whole cells (LMNO//Graphite) with and without compound Bis(2-cyanoethyl)butylmethylphosphonium bis(fluorosulfonyl)imide (P14(2CN)2FSI) at a charge and discharge rate of 0.5 C between 2V to 5V compared to Li+/Li at 20°C.

: Graph showing the charge/discharge profiles of the cell (LMNO//LTO) at charge and discharge rates of 0.05 C, 0.2 C and 0.5 C from 1.2 V to 3.5 V versus Li+/Li for 1M LiFSI electrolyte in PYR13FSI + 0.126 mol/kg Bis(2-cyanoethyl)propylmethylphosphonium bis(fluorosulfonyl)imide (P13(2CN)2FSI) at 20 °C.

: Graph showing the charge/discharge profiles of the cell (LMNO//LTO) at charge and discharge rates of 0.05 C, 0.2 C and 0.5 C from 1.2 V to 3.5 V versus Li+/Li for 1M LiFSI electrolyte in PYR13FSI at 20 °C.

: Graph showing discharge capacities and coulombic efficiencies versus number of cycles for whole cells (LMNO//LTO) with and without compound Bis(2-cyanoethyl)propylmethylphosphonium bis(fluorosulfonyl)imide (P13(2CN)2FSI) at different charge and discharge rates from 1.2 V to 3.5 V versus Li+/Li at 20°C.

: Graph showing discharge capacities and coulombic efficiencies versus number of cycles for whole cells (NMC622//Gr) with and without P14(2CN)2FSI compound at different charge and discharge rates from 2 V to 4.2 V compared to Li+/Li at room temperature (RT).

: Graph showing discharge capacities and coulombic efficiencies versus number of cycles for whole cells (NMC622//Gr) with and without compound Bis(2-cyanoethyl)butylmethylphosphonium bis(fluorosulfonyl)imide (P14(2CN)2FSI) long cycling in C/2 from 2 V to 4.2 V compared to Li+/Li at room temperature (TA).

: Graph showing discharge capacities and coulombic efficiencies versus number of cycles for whole cells (NMC532//Graphite) with and without bis(2-cyanoethyl)ethylmethylphosphonium bis(fluorosulfonyl)imide compound

(P12(2CN) ₂ FSI) at different charge and discharge rates between 2.5 V to 4.2 V versus Li+/Li at 45°C.

EXAMPLES

EXAMPLE 1: Preparation of the electrolyte and button batteries

In a glove box under an inert atmosphere (Argon) with water and O ₂ contents less than 1 ppm, the metal salt is dissolved in an aprotic organic solvent in a desired concentration. One or more compounds are then added and mixed to obtain a homogeneous electrolyte solution.

The complete button cells (CR2032) are assembled in a glove box under an argon atmosphere with contents of less than 1 ppm in O ₂ and H ₂ O. The electrodes used are commercial and they were purchased already coated on the collectors. current (aluminum and copper). They have capacities between 1 and 4 mAh/cm ² and are cut into discs of 13 mm in diameter.

The electrodes are separated by a 16 mm diameter separator with a thickness of between 11 and 180 µm which can be based on different materials. The separator is then soaked with electrolyte. The button cells were then sealed by a button cell crimping instrument to obtain a battery before carrying out the electrochemical characterizations.

Electrochemical impedance spectroscopy (EIS) and galvanostatic cycling measurements were performed using a VMP3 potentiostat (BioLogic) and a multi-channel battery cycler (Arbin Inc). Impedance measurements (EIS) were performed on two-electrode cells at open-circuit bias by applying a 10 mV RMS sine wave at frequencies ranging from 1 MHz to 10 mHz.

Galvanostatic cycling is achieved by charging and discharging cells at different constant currents at the maximum and minimum cut-off voltages specific to the different combinations of active materials.

The impedances and galvanostatic cycling were carried out in a climatic chamber maintaining a constant temperature of 20°C.

EXAMPLE 2: PREPARING A BATTERY LMNO//Graphite WITH AND WITHOUT COMPOUND [P1(2CN) ₃ FSI] and CHARGING AND DISCHARGING THE BATTERY

In a glove box under an inert atmosphere (Argon) with a water and O ₂ content less than 1 ppm, the lithium salt LiFSI (0.936 g) is dissolved in the ionic liquid PYR13FSI (6.045 g) to obtain the desired concentration, the compound (2-cyanoethyl)phosphonium P1(2CN) ₃ FSI (0.170 g) is then added and mixed in order to obtain a homogeneous electrolyte solution.

The batteries were prepared according to the method described in Example 1. Table 1 below groups together the different cathode/anode/electrolyte combinations tested in the battery.

Table 1 : LMNO cathode/Graphite anode/electrolyte combinations tested in a battery.

The batteries were tested in galvanostatic cycling from 2 to 5 V at different C rates: 0.1 C and 0.5 C in a climatic chamber at 20 °C.

There , in which the electrolyte contains the compound P1(2CN) ₃ FSI, shows a discharge capacity loss of 7% between 0.1C and 0.5C respectively 114.54 mAh/g and 106.33 mAh/g. As the charging and discharging speed increases, the polarization between charging and discharging increases. For cycling at 0.5 C, the loss of discharge capacity in 450 cycles is 18.5% (from 114.54 to 93.30 mAh/g).

There , in which the electrolyte does not contain the compound P1(2CN) ₃ FSI shows a discharge capacity loss of 38% between 0.1 C and 0.5 C respectively 118.54 mAh/g and 73.22 mAh/g. For charges and discharges at a rate of 0.5 C, the profiles differ slightly from those of 0.1 C. In fact, the transition plateaus are less well defined, more particularly that of 4.56 V.

By comparing the charge/discharge profiles of the two systems, those containing the (2-cyanoethyl)phosphonium compound are more stable.

Painting 2 : Characteristics of batteries with an LMNO//Graphite system at 0.5 C with and without (2-cyanoethyl)phosphonium compound.

Table 2 and show the discharge capacity as a function of number of cycles of the two systems, with and without (2-cyanoethyl)phosphonium salt compound as well as their coulombic efficiencies.

Without the (2-cyanoethyl)phosphonium salt compound, the discharge capacity of the battery decreases from the first cycles for charge and discharge speeds of 0.5 C unlike the system containing the (2-cyanoethyl)phosphonium compound for which capacity remains stable longer, 12% capacity loss in 450 cycles (106.23mAh/g to 93.39mAh/g) at 100% DoD. The coulombic efficiency is also higher for the electrolyte containing (2-cyanoethyl)phosphonium, it is closer to 99.9% compared to 99.2% without it.

EXAMPLE 3: PREPARATION OF AN LMNO//Graphite BATTERY WITH AND WITHOUT COMPOUND [P14(2CN) ₂ FSI] and CHARGING AND DISCHARGING THE BATTERY

In a glove box under an inert atmosphere (Argon) with a water and O ₂ content less than 1 ppm, the lithium salt LiFSI (0.936 g) is dissolved in the ionic liquid PYR13FSI (6.045 g) to obtain the desired concentration, a (2-cyanoethyl)phosphonium compound P14(2CN) ₂ FSI (0.172 g) is then added and mixed in order to obtain a homogeneous electrolyte solution.

The batteries were prepared according to the method described in Example 1. Table 3 below groups together the different cathode/anode/electrolyte combinations tested in the battery.

Table 3 : LMNO cathode/Graphite anode/electrolyte combinations tested in a battery.

The batteries were tested in galvanostatic cycling from 2 to 5 V at different C rates: 0.1 C and 0.5 C in a climatic chamber at 20 °C.

There , in which the electrolyte contains the compound P14(2CN) ₂ FSI, shows a discharge capacity loss of 7.5% between 0.1 C and 0.5 C respectively 124.08 mAh/g and 114.73 mAh/g. As the charging and discharging speeds increase, the polarization between charging and discharging increases. For cycling at 0.5 C, the loss of discharge capacity in 243 cycles is 4.5% (from 114.73 to 109.63mAh/g).

There , in which the electrolyte does not contain the compound P14(2CN) ₂ FSI, shows a loss of discharge capacity of 9% between 0.1 C and 0.5 C respectively 117.19 mAh/g and 107.02 mAh/g. At a charge and discharge speed of 0.2 C, the discharge capacity decreases by 13% between the 10th and the 247th cycle in C/2, going from 107.02mAh/g to 93.39mAh/g.

The capacity loss is less significant for the system in which the electrolyte contains the compound P14(2CN) ₂ FSI.

Table 4 : Characteristics of batteries with an LMNO//Graphite system at 0.5 C with and without P14(2CN) ₂ FSI compound.

Table 4 and show the discharge capacity as a function of number of cycles of the two systems, with and without (2-cyanoethyl)phosphonium salt compound.

Without the P14(2CN) ₂ FSI compound, the discharge capacity of the first cycle at a charge and discharge rate of 0.5 C is lower than with the (2-cyanoethyl)phosphonium compound (respectively 107.99 mAh/g and 115.30 mAh/g). Concerning cyclability, the capacity of the system containing the P14(2CN) ₂ FSI compound is more stable during cycles. Indeed, taking into account the first 247 cycles, the loss of capacity for the system without the compound P14(2CN) ₂ FSI is 13.1% compared to 4.9% for that containing the compound P14(2CN) ₂ FSI. The coulombic efficiency is also higher for the electrolyte containing (2-cyanoethyl)phosphonium.

EXAMPLE 4: PREPARATION OF AN LMNO BATTERY// LTO WITH AND WITHOUT COMPOUND [P13(2CN) ₂ FSI] and CHARGING AND DISCHARGING THE BATTERY

In a glove box under an inert atmosphere (Argon) with a water and O ₂ content less than 1 ppm, the lithium salt LiFSI (0.936 g) is dissolved in the ionic liquid PYR13FSI (6.045 g) to obtain the desired concentration, a (2-cyanoethyl)phosphonium compound P13(2CN) ₂ FSI (0.331 g) is then added and mixed in order to obtain a homogeneous electrolyte solution.

The batteries were prepared according to the method described in Example 1. Table 5 below groups together the different cathode/anode/electrolyte combinations tested in the battery.

Table 5 : LMNO cathode/LTO anode/electrolyte combinations tested in battery.

The batteries were tested in galvanostatic cycling from 1.2 to 3.5 V at different C rates: 0.05 C, 0.1 C, 0.14 C, 0.2 C, 0.33 C and 0.5 C in a climatic chamber at 20 °C.

There , in which the electrolyte contains the compound P13(2CN) ₂ FSI, shows a discharge capacity loss of 14% between 0.05 C and 0.5 C respectively 141.08 mAh/g and 121.44 mAh/g. As the charging and discharging speed increases, the polarization between charging and discharging increases.

There , in which the electrolyte does not contain the compound P13(2CN) ₂ FSI, shows a loss of discharge capacity of 30% between 0.05 C and 0.5 C respectively 131.54 mAh/g and 91.22 mAh/g. From the rate 0.2 C, the charge/discharge profile differs from 0.05 C. In fact, the disappearance of one of the transition plateaus is observed around 2.5 V, this may be due to an irreversible consumption of Li ⁺ ions during the formation of passivation films on the surface of the electrodes. When there are no longer enough Li ⁺ ions to participate in the Mn ₄ ⁺ /Mn ₃ ⁺ conversion process, the transition plateau disappears.

By comparing the charge/discharge profiles of the two systems, the one containing the (2-cyanoethyl)phosphonium compound in is more stable because no transition plateau disappears during the cycles. This compound of P13(2CN) ₂ FSI plays a role in the formation of the passivation film and therefore reduces the irreversible consumption of Li ⁺ ions during the cycles.

Painting 6 : Characteristics of batteries with an LMNO//LTO system at 0.05 C and 0.5 C with and without compound.

Table 6 and the show the discharge capacity of both systems, with and without (2-cyanoethyl)phosphonium salt compound.

Without P13(2CN) ₂ FSI compound, the discharge capacity of the battery decreases from C/10 unlike the system containing the (2-cyanoethyl)phosphonium compound for which the capacity remains stable longer and higher for rates of C up to 0.5 C. The coulombic efficiency is also higher with the formulation containing (2-cyanoethyl)phosphonium.

EXAMPLE 5: PREPARING A BATTERY NMC622 //Graphite WITH AND WITHOUT COMPOUND [P14(2CN) ₂ FSI] and CHARGING AND DISCHARGING THE BATTERY

In a glove box under an inert atmosphere (Argon) with a water and O2 content less than 1ppm, the lithium salt LiFSI (1.00g) is dissolved in the ionic liquid EMIMFSI (6.49g) in a desired concentration, a compound in (2-cyanoethyl)phosphonium P14(2CN)2FSI (0.184g) is then added and mixed to obtain a homogeneous solution.

The batteries were prepared according to the method described in Example 1.

Table 7 : NMC622 cathode/electrolyte/Graphite anode combinations tested in battery.

The batteries were tested in galvanostatic cycling from 2 to 4.2V at different C rates: 0.05C, 0.1C, 0.14C, 0.2C, 0.33C and 0.5C at room temperature (RT).

Table 8 : Characteristics of batteries with an NMC622//Gr system at 0.05 C and 0.5 C with and without compound.

Table 8 and Figures 10 and 11 show the discharge capacity as a function of number of cycles of the two systems, with and without compound. There shows the first 60 cycles and the shows the continuation of cycles at C/2 up to 250 cycles at room temperature.

Without the compound, the discharge capacity of the battery gradually decreases unlike the system containing the (2-cyanoethyl)phosphonium compound for which the capacity at different charge and discharge speeds is better preserved. There shows that the effect is even more marked on the return to charge and discharge rates of 0.1 C, where the retention capacity of the discharge capacity is significantly lower without the (2-cyanoethyl)phosphonium than with. The coulombic efficiency is also higher with the formulation containing (2-cyanoethyl)phosphonium.

EXAMPLE 6: Comparison table showing the impact of the number of functions nitrile on the concentration necessary to achieve the effectiveness of the molecule.

Table 9 Comparative table showing the ratio Molar mass of the molecule/Number of nitrile function carried by the molecule.

For the same electrode system, when using P1(2CN) ₃ FSI, 129g of molecule will be required whereas for P14(2CN) ₂ FSI, 195g of molecule will be required for the same efficiency, which generates a higher concentration and therefore a reduction in conductivity.

Table 10 : At equivalent concentration of products (electrolyte compound), the capacity retentions with molecules containing two or three nitrile functions are greater than with molecules containing a single nitrile function.

Example 7: PREPARATION OF AN NMC532//GRAPHITE BATTERY WITH AND WITHOUT COMPOUND [P12(2CN)2FSI] and CHARGING AND DISCHARGE OF THE BATTERY

In a glove box under an inert atmosphere (Argon) with a water and O ₂ content less than 1 ppm, the lithium salt LiFSI (0.936 g) is dissolved in the ionic liquid PYR13FSI (6.045 g) to obtain the desired concentration, a (2-cyanoethyl)phosphonium compound P12(2CN) ₂ FSI (0.320 g) is then added and mixed in order to obtain a homogeneous electrolyte solution.

The batteries were prepared according to the method described in Example 1. Table 11 below groups together the different cathode/anode/electrolyte combinations tested in the battery.

Painting 1 1 : Battery tested NMC532 cathode/Graphite anode/electrolyte combinations.

The batteries were tested in galvanostatic cycling from 2.5 to 4.2 V at different C rates: 0.05 C, 0.1 C, 0.14 C, 0.2 C, 0.33 C and 0.5 C in a climatic chamber at 45 °C.

Table 1 2 : Characteristics of batteries with an NMC532//Graphite system at 0.05 C and 0.5 C with and without compound

Table 12 and the show the discharge capacity as a function of number of cycles of the two systems, with and without (2-cyanoethyl)phosphonium salt compound at 45 °C.

There , in which the electrolyte contains the compound P12(2CN) ₂ FSI, shows a loss of discharge capacity of 8.6% between 0.05 C and 0.5 C respectively 1.5 mAh/cm² and 1.37 mAh/cm² against a loss of discharge capacity of 16% for the electrolyte not containing the (2-cyanoethyl)phosphonium compound.

There shows that the capacity at a rate of 0.05C for the electrolyte containing the compound P12(2CN) ₂ FSI is greater than in the electrolyte not containing the compound, 1.50 mAh/cm² against 1.06mAh/cm².

Without P12(2CN) ₂ FSI compound, the discharge capacity of the battery is not stable from the first cycles unlike the system containing the (2-cyanoethyl)phosphonium compound for which the discharge capacity remains stable longer and is higher for C levels up to 0.5 C. The coulombic efficiency is also higher with the formulation containing (2-cyanoethyl) phosphonium.

Claims (29)

Electrolyte compound comprising a (2-cyanoethyl)phosphonium salt as represented by formula (I):
(I)
in which :
-
R1 is independently selected from unsubstituted -CH ₂ -CH ₂ -CN chain, C1-C20 alkyl, C3-C6 cycloalkyl, C2-C20 alkenyl, C5-C8 cycloalkenyl, C2 alkynyl -C20, a vinylbenzyl group; in which the hydrogen atoms can be substituted by a fluorine, a -CF ₃ , an ether, an alkyl group, a perfluorinated alkyl group, a silyl group, a siloxy group, a sulfoxide group, a nitrile group, a thioether group or their combinations.
R2 is independently selected from a C1-C20 alkyl group, a C3-C6 cycloalkyl, a C2-C20 alkenyl, a C5-C8 cycloalkenyl, a C2-C20 alkynyl, a vinylbenzyl group; in which the hydrogen atoms can be substituted by a fluorine, a -CF ₃ , an ether, an alkyl group, a perfluorinated alkyl group, a silyl group, a siloxy group, a sulfoxide group, a nitrile group, a thioether group or their combinations. Electrolyte compound according to claim 1 in which R1 is chosen from unsubstituted -CH ₂ -CH ₂ -CN chain, a C1 -C10 alkyl in which the hydrogen atoms can be substituted by a fluorine, a -CF3, an ether, an alkyl group, a perfluorinated alkyl group, a silyl group, a siloxy group, a sulfoxide group, a nitrile group, a thioether group or combinations thereof; and R2 is a C1 -C10 alkyl in which the hydrogen atoms can be substituted by a fluorine, a -CF3, an ether, an alkyl group, a perfluorinated alkyl group, a silyl group, a siloxy group, a sulfoxide group , a nitrile group, a thioether group or combinations thereof. Electrolyte compound according to claim 2 in which R1 is chosen from a methyl or a C1-C4 alkyl in which the hydrogen atoms can be substituted by a fluorine, a -CF3, an ether, an alkyl group, an alkyl perfluorinated, silyl, siloxy, sulfoxide, nitrile, thioether or combinations thereof; and in which R2 is chosen from methyl, ethyl, propyl, iso-butyl, n-butyl or allyl. Electrolyte compound according to claim 1 in which:
-
R1 is independently selected from C1-C20 alkyl, C3-C6 cycloalkyl, C2-C20 alkenyl, C5-C8 cycloalkenyl, C2-C20 alkynyl, vinylbenzyl group; in which the hydrogen atoms may be substituted by a fluorine, a -CF3, an ether, an alkyl group, a perfluorinated alkyl group, a silyl group, a siloxy group, a sulfoxide group, a thioether group or combinations thereof.
R2 is independently chosen from a C1-C20 alkyl group, a C3-C6 cycloalkyl, a C2-C20 alkenyl, a C5-C8 cycloalkenyl, a C2-C20 alkynyl, by a vinylbenzyl group; in which the hydrogen atoms may be substituted by a fluorine, a -CF3, an ether, an alkyl group, a perfluorinated alkyl group, a silyl group, a siloxy group, a sulfoxide group, a thioether group or combinations thereof. Electrolyte compound according to claim 4 in which R1 and R2 are independently chosen from a C1-C10 alkyl in which the hydrogen atoms can be substituted by a fluorine, a -CF3, an ether, an alkyl group, a group perfluorinated alkyl, a silyl group, a siloxy group, a sulfoxide group, a thioether group or combinations thereof. Electrolyte compound according to claim 5 in which R1 is chosen from a methyl or a C1-C4 alkyl in which the hydrogen atoms can be substituted by a fluorine, a -CF3, an ether, an alkyl group, a group perfluorinated alkyl, a silyl group, a siloxy group, a sulfoxide group, a thioether group or combinations thereof; and R2 is selected from methyl, ethyl, propyl, iso-butyl, n-butyl or allyl. Electrolyte compound according to one of Claims 1 to 6 in which the anion is chosen from bis(fluorosulfonyl)imide (FSI), bis(trifluoromethanesulfonyl)imide (TFSI), tetrafluoroborate, hexafluorophosphate, dicyanamide, triflate, 4.5 -dicyano-2-(trifluoromethyl)imidazolate, fluorosulfonyl(trifluoromethanesulfonyl)imide, bis(oxalato)borate, difluorobis(oxalato)borate, acetate., N-ethyl-N-methyl-functionalized sulfonimide, (difluoromethanesulfonyl)(trifluoromethanesulfonyl)imide, (methanesulfonyl)(trifluoromethanesulfonyl)imide, (difluoromethanesulfonyl)(fluoromethanesulfonyl)imide, (methanesulfonyl)(fluoromethanesulfonyl)imide. Electrolyte compound according to claim 7 in which the anion X- is chosen from FSI or TFSI. Electrolyte compound according to claim 1, the (2-cyanoethyl)phosphonium salt of which is represented by formula (II):
(II)
in which
- And
R2 is independently chosen from a C1-C20 alkyl group, a C3-C6 cycloalkyl, a C2-C20 alkenyl, a C5-C8 cycloalkenyl, a C2-C20 alkynyl, by a vinylbenzyl group; in which the hydrogen atoms can be substituted by a fluorine, a -CF ₃ , an ether, an alkyl group, a perfluorinated alkyl group, a silyl group, a siloxy group, a sulfoxide group, a thioether group or combinations thereof. Electrolyte compound according to claim 9 in which R2 is a C1-C10 alkyl in which the hydrogen atoms can be substituted by a fluorine, a -CF3, an ether, an alkyl group, a perfluorinated alkyl group, a group silyl, a siloxy group, a sulfoxide group, a thioether group or combinations thereof. Electrolyte compound according to claim 10 in which R2 is chosen from a C1-C4 alkyl in which the hydrogen atoms can be substituted by a fluorine, a -CF3, an ether, an alkyl group, a perfluorinated alkyl group, a silyl group, a siloxy group, a sulfoxide group, a thioether group or combinations thereof. An electrolyte compound according to claim 11 wherein R2 is selected from methyl, ethyl, propyl, iso-butyl, n-butyl or allyl. Electrolyte compound according to one of claims 9 to 12 in which the anion is chosen from bis(fluorosulfonyl)imide (FSI), bis(trifluoromethanesulfonyl)imide (TFSI), tetrafluoroborate, hexafluorophosphate, dicyanamide, triflate, 4.5 -dicyano-2-(trifluoromethyl)imidazolate, fluorosulfonyl(trifluoromethanesulfonyl)imide, bis(oxalato)borate, difluorobis(oxalato)borate, acetate., N-ethyl-N-methyl-functionalized sulfonimide, (difluoromethanesulfonyl)(trifluoromethanesulfonyl)imide, (methanesulfonyl)(trifluoromethanesulfonyl)imide, (difluoromethanesulfonyl)(fluoromethanesulfonyl)imide, (methanesulfonyl)(fluoromethanesulfonyl)imide. Electrolyte compound according to claim 13 wherein the anion X- is chosen from FSI or TFSI. An electrolyte compound according to claim 1 wherein the (2-cyanoethyl)phosphonium salt is in the form of a phosphonium salt dimer, said dimer being represented by formula (III)
(III)
in which
Z is chosen from C1-C20 alkyl di-radicals of type –(CH ₂ ) _n – which may comprise one or more ethers or which may comprise one or more sequences of type –CH ₂ –Y–CH ₂ – with Y=S or SO or SO2; preferably the alkyl di-radical is an ethyl, propyl, butyl or pentyl di-radical;
-
R2 is independently selected from an unsubstituted -CH2-CH2-CN chain, by a C1-C20 alkyl, a C3-C6 cycloalkyl, a C2-C20 alkenyl, a C5-C8 cycloalkenyl, a C2-alkynyl C20, a vinylbenzyl group; in which the hydrogen atoms may be substituted with fluorine, -CF3, ether, alkyl, perfluorinated alkyl, silyl, siloxy, sulfoxide, nitrile, thioether or combinations thereof; Electrolyte compound according to claim 15 in which R2 is a C1 -C10 alkyl in which the hydrogen atoms can be substituted by a fluorine, a -CF3, an ether, an alkyl group, a perfluorinated alkyl group, a group silyl, a siloxy group, a sulfoxide group, a thioether group or combinations thereof. Electrolyte compound according to claim 16 in which R2 is chosen from a methyl or a C1-C4 alkyl in which the hydrogen atoms can be substituted by a fluorine, a -CF3, an ether, an alkyl group, a group perfluorinated alkyl, a silyl group, a siloxy group, a sulfoxide group, a thioether group or combinations thereof; and R2 is selected from methyl, ethyl, propyl, iso-butyl, n-butyl or allyl. Electrolyte compound according to one of claims 15 to 17 in which the anion is chosen from bis(fluorosulfonyl)imide (FSI), bis(trifluoromethanesulfonyl)imide (TFSI), tetrafluoroborate, hexafluorophosphate, dicyanamide, triflate, 4.5 -dicyano-2-(trifluoromethyl)imidazolate, fluorosulfonyl(trifluoromethanesulfonyl)imide, bis(oxalato)borate, difluorobis(oxalato)borate, acetate., N-ethyl-N-methyl-functionalized sulfonimide, (difluoromethanesulfonyl)(trifluoromethanesulfonyl)imide, (methanesulfonyl)(trifluoromethanesulfonyl)imide, (difluoromethanesulfonyl)(fluoromethanesulfonyl)imide, (methanesulfonyl)(fluoromethanesulfonyl)imide. Electrolyte compound according to claim 18 wherein the anion X- is chosen from FSI or TFSI. Electrolyte composition comprising a lithium salt or a sodium salt, an aprotic organic solvent and an electrolyte compound as defined in one of claims 1 to 19. An electrolyte composition according to claim 20 wherein said aprotic organic solvent is selected from an ionic liquid, a carbonate, a glyme, an alkyl sulfonamide or a mixture thereof. Electrolyte composition according to claim 20 or 21 in which the ionic liquid comprises (i) a cation chosen from an imidazolium, or based on pyrrolidinium, morpholinium, pyridinium, piperidinium, phosphonium, ammonium and (ii ) an anion chosen from hexafluorophosphate (PF6), tetrafluoroborate (BF4), bis(trifluoromethanesulfonyl)imide (TFSI), bis(fluorosulfonyl)imide (FSI), dicyanamide (DCA), 4,5-dicyano -2-(trifluoromethyl)imidazolide (TDI), fluorosulfonyl-(trifluoromethanesulfonyl)imide (FTFSI), (difluoromethanesulfonyl)(trifluoromethanesulfonyl)imide (DFTFSI), bis(oxalato)borate (BOB), difluoro(oxalato)borate (DFOB). Electrolyte composition according to one of claims 20 to 22 comprising a lithium or sodium salt, an electrolyte compound as defined in one of claims 1, 4 or 9 and an ionic liquid. Battery comprising a cathode, an anode, a separator and an electrolyte composition as defined in one of claims 20 to 22. Battery according to claim 24 where the separator and the electrolyte are identical. Battery comprising a cathode, a separator and an electrolyte composition as described in one of claims 20 to 23. Battery according to one of claims 24 to 26 in which the cathode is chosen from

1. For a lithium battery: a lithium intercalating compound, chosen from lithium-iron phosphate, (LiFePO4), lithium-nickel-manganese-cobalt oxide, (LiNixMnyCozO2), lithium-nickel-manganese-oxide doped cobalt, (LiNixMnyCozO2), lithium cobalt oxide (LiCoO2), doped lithium cobalt oxide, lithium nickel oxide (LiNiO2), doped lithium nickel oxide, oxide lithium manganese (LiMn2O4), doped lithium manganese oxide, NCA, lithium vanadium oxide, doped lithium vanadium oxide, lithium and mixed metal oxides, Lithium Manganese Nickel Oxide ( LMNO), mixed lithium and transition metal oxides, doped lithium and mixed transition metal oxides (NCA, LMNX,), lithium vanadium phosphate, lithium manganese phosphate, lithium phosphate -cobalt, lithium and mixed metal phosphates, metal sulfides and their combinations.
2. For a Sodium-ion battery: a metal oxide such as VO2, V2O5, H2V3O8, b-MnO2;

layered NaMOX such as Na0.71CoO2, Na0.7MnO2, b-NaMnO2, Na1.1V3O7.9, Na2RuO3, Na2/3[Ni1/3Mn2/3]O2, Na0.67Co0.5Mn0.5O2, Na0.66Li0. 18Mn0.71Ni0.21Co0.08O2+x;
1D tunnel oxides such as Na0.44MnO2,Na0.66[Mn0.66Ti0.34]O2, Na0.61[Mn0.27Fe0.34Ti0.39]O2;
fluorides such as FeO0.7F1.3 and NaFeF3;
sulfates such as Na2Fe2(SO4)3 and Eldfellite NaFe(SO4)2;
NaFePO4 and FePO4 phosphates; Na3V2(PO4)3, Na3V2(PO4)3, Na3V2(PO4)3@C@rGO, Na3V2(PO4)3/C, NaVOPO4;
pyrophosphates such as Na2CoP2O7, Na2FeP2O7 and Na3.12Fe2.44(P2O7)2;
fluorophosphates such as NaVPO4F, Na3V2(PO4)2F3, Na3V2O2(PO4)2F@RuO2, Na3(VO1-xPO4)2F1+2x, Na3.5V2(PO4)2F3;
mixed phosphates such as Na7V4(P2O7)4(PO4), Na3MnPO4CO3;
hexacyanometalates such as MnHCMn PBAs, Na1.32Mn[Fe(CN)6]0.83.3.5H2O, NaxCo[Fe(CN)6]0.90·2.9H2O;
critical metal-free cathodes such as Na2C6O6, Na6C6O6, SSDC, C6Cl4O2/CMK, PTCDA-PI, poly(anthraquinonyl imide)s and functionalized graphite;
analogues of Prussian white
Prussian blue analogues Battery according to one of claims 24, 25 or 27 in which the anode is chosen from:

1. For a Lithium-ion battery:

a composite titanium oxide containing lithium;
mixture of niobium oxides (XNO);
metals (Me) such as Si, Sn, Li, Zn, Mg, Cd, Ce, Ni and Fe or alloys thereof;
graphite, graphene, including particles of natural graphite, artificial graphite, meso-carbon microbeads (MCMB) and carbon (including soft carbon, hard carbon, carbon nanofibers and carbon nanotubes ;
silicon (Si), silicon/graphite composites, silicon combinations of germanium (Ge), tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), zinc (Zn), aluminum (Al), nickel (Ni), cobalt (Co), manganese (Mn), titanium (Ti), iron (Fe) and cadmium (Cd);
alloys or intermetallic compounds of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al or Cd with other elements, said alloys or compounds being stoichiometric or non-stoichiometric;
oxides, carbides, nitrides, sulphides, phosphides, selenides and tellurides of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Fe, Ni, Co, Ti, Mn or Cd, and their mixtures or composites;
oxides (MeOx) of metals (Me);
and composites of metals (Me) with carbon;
MXene materials, [M_xC where X = 2,3,4).

1. For a Sodium-ion battery: materials based on oxides, sulfides, selenides, phosphides and MOFs and carbon-based materials; carbon-based materials include expanded graphite, N-doped expanded graphite , carbon black, amorphous carbon, carbon microspheres, hard carbon, meso-strong soft carbon, carbon nanotubes, graphene nanosheets, nitrogen-doped CNTs, N-doped graphene foam , N-doped porous nanofibers, microporous carbon and cube-shaped porous carbon; oxides include MnO2 nanoflowers, NiO nanosheets, porous SnO, porous SnO2 nanotubes, porous 3D Fe3O4–C, porous CuO-RGO, ultrasmall nitrogen-doped MnO-CNTs, micro- CuS flowers, SnS2-RGO, Co3S4-PANI, ZnS-RGO, NiS-RGO, Co3S4-PANI, MoS2–C, nitrogen-doped conductive WS2-carbon nanosheets, Sb3Se3-RGO nanorods, MoSe2 -carbon fiber, multi-shell Sn4P3 nanostructures, Sn4P3–C nanospheres, Se4P4, CoP nanoparticles, FeP nanorod arrays on carbon fabric, MoP-C, CUP2-C, graphene NiO/ Neither hollow, yellow-shell structured CoSe/C doped with nitrogen; the metal of Na.

Battery according to claim 24 in which when the cathode is LMNO then the anode is graphite or LTO; when the cathode is made of NMC532 then the anode is made of graphite; when the cathode is made of NMC622 then the anode is made of graphite; when the cathode is made of LFP then the anode is made of graphite; when the cathode is LFP then the anode is LTO.