KR20010022605A - Process for preparing perfluoroalkane-1-sulfonyl(perfluoroalkylsulfonyl)imide-n-sulfonyl-containing methanides, imides and sulfonates, and perfluoroalkane-1-n-sulfonylbis(perfluoroalkylsulfonyl)methanides - Google Patents

Abstract

The present invention provides a secondary lithium comprising a compound of formula (I), a process for preparing the compound, the use of the compound in an electrolyte system as a conductive salt of a lithium battery and an electrolyte for a lithium battery comprising the compound of formula (I) as well as a corresponding electrolyte. It's about the battery itself:

Formula I

M ₂ [R ₁ -SO _2- (CF ₂ ) _n -SO ₂ -R]

Where

R is C (SO ₂ R _F ) ₂ , N (SO ₂ R _F ) or O,

R ₁ is C (SO ₂ R _F ) ₂ or N (SO ₂ R _F ),

R and R ₁ are independent of each other,

R _F is (C _x F _{2x + 1} ),

M is a counter ion selected from the group consisting of Li, Na, K, Cs, Rb, Be _1/2 , Mg _1/2 , Sr _1/2 and Ba _1/2 ,

n is 1, 2 or 3,

x is 1, 2, 3 or 4.

Description

Peramides, imides and sulfonates, including perfluoroalkane-1-sulfonyl (perfluoroalkylsulfonyl) imide-ene-sulfonyl, and perfluoroalkane-1-ene-sulfonylbis ( PROFESSION FOR PREPARING PERFLUOROALKANE-1-SULFONYL

Literature discloses lithium compounds such as Li [F ₃ CSO ₃ ] (lithium triflate) which are simple in production and consequently commercially available. However, the corresponding compounds are unsuitable for use in secondary batteries because the conductivity of the compounds is too low in typical aprotic solvents used in secondary batteries (Volkov, OV; Skudin, AM; Ignat). 'ev, NV; Soviet Electrochemistry, 1992, 28, 1527). Conversely, lithium tris (trifluoromethylsulfonyl) methanide (Li [C (SO ₂ CF ₃ ) ₃ ]) and lithium bis (trifluoromethylsulfonyl) imide (Li [N (SO ₂ CF ₃ ) ₂ ]) shows very high solubility and conductivity in aprotic solvents (Levy, SC; Cieslak, WR; "Review of Lithium-Ion Technology", Sandia National Laboratories, Exploratory Batteries Dept. 2223, Albuquerque, NM 87185 -0614, 1994; Dominey, LA; "Anodic Corrosion Processes Relevant to Lithium Batteries Employing High Voltage Cathodes", Proc. 10th Int. Seminar on Prim. And Second.Battery Tech. And Appl., Florida Educational Seminars, Inc. Boca Raton , Fl. 1993). However, even these compounds are of limited suitability for use in lithium batteries, because Li [N (SO ₂ CF ₃ ) ₂ ] is highly corrosive (Levy, SC; Cieslak, WR; "Review of Lithium- Ion Technology "Sandia National Laboratories, Exploratory Batteries Dept. 2223, Albuquerque, NM 87185-0614, 1994). Li [C (SO ₂ CF ₃ ) ₃ ] has a content of 1.66%, which is low in lithium.

U. S. Patent No. 5514493 also discloses better electrolyte properties, specifically corrosive, by combining sulfonates, sulfonylimides and sulfonylmethanides with perfluoromorpholine, perfluoropiperazine and perfluorinated amines. Attempts are being made to obtain a system. Suitable combinations provide a dianionic system. Similarly, other researchers have described bivalent anionic systems of similar composition (Razaq et al., Case Cent. Electrochem. Sci., Case Western Reserve Univ., Cleveland, OH, USA Report (1989), GRI-89). / 0025; Order No. PB89-178768, 214 pp. Avail .: from Geov.Rep.Announce.Index. (US) 1989, 89 (12), Abstr. No. 932, 621; AJ Appleby et al. Cent. Electrochem Syyt.Hydrogen Res., Texas A and M Univ.System, College Station, TX, 77843-3402, USA, Morgantown Energy Technol.Cent., [Rep.] DOE / METC (US Dep. Energy). 1991 DOE / METC-91 / 6120, Proc.Annu.Fuel Cells Contract.Rev.Meet. 3rd, 1991, 169-177). Razaq et al. Have a crosslinked α, ω in the report for fuel cells represented by the formula II, ie F ₃ CSO ₂ -NH-SO _2- (CF ₂ ) ₄ -O ₂ S-NH-SO ₂ CF ₃ . -Perfluoroalkane-bis [sulfonyltrifluoromethyl-sulfonylimide] is described.

Subsequent papers (DD DesMarteau, "Novel Perfluorinated Ionomers and Ions", Proceedings of international conference on Fluorine Chemistry 27-30, July 1994, Kyoto, Japan) disclose the crystal structure of cesium bisimide, and technical characteristics of the compound clearly, which is a very strong acid represent _{"typical" Li [N (sO 2 CF} 3) 2] in analogy to the non-positive excellent conductivity in the magnetic solvents _{-.. (CF 2) 4} - The introduction of longer perfluorinated alkyl chains, such as, reduces the tendency for corrosion, but this adversely affects other properties such as, for example, the result of cationic conductivity and current intensity.

The present invention provides a secondary compound comprising a compound of formula (I), a process for preparing the compound, the use of the compound in an electrolyte system as a conductive salt of a lithium battery and an electrolyte for a lithium battery comprising the compound of formula (I) as well as a corresponding electrolyte. Regarding lithium battery:

M ₂ [R ₁ -SO _2- (CF ₂ ) _n -SO ₂ -R]

Where

R is C (SO ₂ R _F ) ₂ , N (SO ₂ R _F ) or O,

R ₁ is C (SO ₂ R _F ) ₂ or N (SO ₂ R _F ),

R and R ₁ are independent of each other,

R _F is (C _x F _{2x + 1} ),

M is a counter ion selected from the group consisting of Li, Na, K, Cs, Rb, Be _1/2 , Mg _1/2 , Sr _1/2 and Ba _1/2 ,

n is 1, 2 or 3,

x is 1, 2, 3 or 4.

Accordingly, it is an object of the present invention to provide suitable lithium salts which have a suitable lithium content and exhibit corrosion stability and which do not generate harmful reverse potential due to negative charges moving in opposite directions while having a cationic conductivity that is superior to known comparable lithium salts. .

The object is a novel compound of formula (I), a process for its preparation, the use of said compound in an electrolyte system as a conductive salt of a lithium battery and a secondary electrolyte comprising a corresponding electrolyte as well as an electrolyte for a lithium battery comprising a compound of formula (I) Made by lithium battery:

Formula I

M ₂ [R ₁ -SO _2- (CF ₂ ) _n -SO ₂ -R]

Where

R is C (SO ₂ R _F ) ₂ , N (SO ₂ R _F ) or O,

R ₁ is C (SO ₂ R _F ) ₂ or N (SO ₂ R _F ),

R and R ₁ are independent of each other,

R _F is (C _x F _{2x + 1} ),

M is a counter ion selected from the group consisting of Li, Na, K, Cs, Rb, Be _1/2 , Mg _1/2 , Sr _1/2 and Ba _1/2 ,

n is 1, 2 or 3,

x is 1, 2, 3 or 4.

The process for preparing the compound of formula (I), which is the subject of the present invention, comprises the steps of: a) reacting perfluoroalkylsulfonyl fluoride with ammonia dissolved in an aprotic solvent, and b) obtaining the amine with sodium hydroxide dissolved in water. Treating to give the corresponding sodium salt, c) reacting the sodium salt with (Me ₃ Si) ₂ NH under heating to give sodium perfluoroalkylsulfonyltrimethylsilylamide of formula III, d) The compound was reacted with 1, n-alkane-bis (sulfonyl fluoride) to provide sodium perfluoroalkane-1-fluorosulfonyl-N-trifluoro-methylsulfonylimide represented by Formula IV. E) reacting the compound of formula IV with sodium perfluoroalkylsulfonyltrimethylsilylamide of formula III and successively reacting in acidic ether solution, aqueous KOH, followed by metathesis of Or di) reacting one equivalent of the compound of formula IV with dilithiated bis- (perfluoroalkylsulfonyl) methane and suitably post-treatment and metathesis of the reaction product obtained Or di) perfluoroalkane-1-sulfonyl- (perfluoroalkyl) of formula VII by reacting a compound of formula IV with an alkaline lithium salt and metathesizing it with a lithium halide Sulfonyl) imide-N-sulfonate is prepared:

Na (R _F SO ₂ NSiMe ₃ )

Na [R _F SO ₂ NSO ₂ (CF ₂ ) _n SO ₂ F]

Li ₂ (R _F SO ₂ NSO _2- (CF ₂ ) _n -SO ₂ NSO ₂ R _F )

Li ₂ (R _F SO ₂ NSO _2- (CF ₂ ) _n -SO ₂ C (SO ₂ R _F ) ₂ )

Li ₂ [R _F SO ₂ NSO ₂ (CF ₂ ) _n SO ₃ ]

Where

n is 1, 2 or 3,

R _F has the above meaning.

In addition, the present invention provides a composition comprising a) bis (perfluoroalkylsulfonyl) methane in an aprotic organic solvent selected from the group consisting of tetrahydrofuran, 2-methyltetrahydrofuran and diethyl ether, Preferably it is lithiated at 10 to 25 ℃, -10 to +50 ℃, in a molar ratio of α, ω-perfluoroalkanebis (sulfonyl fluoride) of the general formula (VIII) and 1: 0.3 to 1: 0.5, Preferably at a temperature of 20 to 30 ° C., then b) in a mineral solution, separating off the solvent, converting to the corresponding divalent anion using alkaline cesium salt in solution, and purifying if necessary C) firstly treated with a mineral acid, preferably hydrochloric acid, in an organic solvent selected from the group consisting of diethyl ether, dibutyl ether and 2-methyltetrahydrofuran, followed by lithium hydroxide water. A compound of formula (I) having the meaning of, characterized in that the conversion of alkali metal bismethacrylate arsenide, R ₁ and R are the same, and _{(C (SO 2 R F)} 2) - by reacting in the liquid D for purposes of the formula Xa Relates to a method of making:

FO ₂ S- (CF ₂ ) _n -SO ₂ F

M ₂ [(R _F CSO ₂ ) ₂ C-SO _2- (CF ₂ ) _n -SO ₂ -C (SO ₂ R _F ) ₂ ]

Where

R _F and n have the above meaning.

In particular, the invention relates to the corresponding dilithium compounds of the formula Xb:

Li ₂ [(R _F SO ₂ ) ₂ C-SO _2- (CF ₂ ) _n -SO ₂ -C (SO ₂ R _F ) ₂ ]

In order to carry out the process according to the invention, a fourth intermediate synthesis starting from trifluoromethylsulfonyl fluoride and ammonia is used to form a first intermediate of formula III to prepare another desired intermediate represented by formula IV. do:

Formula III

Na [R _F -SO ₂ -N-SiMe ₃ ]

Formula IV

Na [R _F SO ₂ NSO _2- (CF ₂ ) _n -SO ₂ F]

In order to prepare the salt, only part of the already obtained [R _F -SO ₂ -N-SiMe ₃ ] sodium salt may be used, since Na [R _F SO ₂ NSO _2- (CF ₂ ) _n -SO ₂ F] corresponds to the corresponding crosslinked dilithium bisimide of Formula V according to standard methods using equimolar amounts of Na [R _F -SO ₂ -N-SiMe ₃ ], such as Li ₂ [F ₃ CSO ₂ N-SO ₂ -NSO ₂ CF ₃ ] wherein R is N (SO ₂ R _F ), R _F is CF ₃ , M is Li and n is 1 according to formula (I).

In contrast, the process for the preparation of dilithium imide methide with mixed composition, for example, uses an equimolar amount of Na [F ₃ CSO ₂ NSO _2- (CF ₂ ) _n -SO ₂ F], where n is 1. By reaction with lithiated bis (trifluoromethylsulfonyl) methane and metathesis to produce the desired lithium salt.

The compounds of formula (I) according to the invention also comprise dilithium imide sulfonates of formula (VII). This compound saponifies a monovalent anion, Na [R _F SO ₂ NSO _2- (CF ₂ ) _n -SO ₂ F], where n is 1 and R _F is CF ₃ in an aqueous solution with a suitable base. By preparing a corresponding divalent anion. Alkaline lithium salts selected from the group consisting of Li ₂ CO ₃ and LiOH.H ₂ O or other compounds are suitable for saponification. Dilithium imide sulfonate can be obtained by metathesis with lithium halides, preferably lithium chloride.

Thus, the present invention relates to a process which can be shown by the following scheme 1 using the lithium compound according to the invention as an example:

Procedure of Scheme 1

As can be expected from the above scheme, the process for preparing the compound according to formula III is carried out in three steps. The inventors have advantageously found that the first reaction step is described by D. D. Des Marteau, M. Witz, J. Fluorine Chem. It has been found that it does not need to be carried out in liquid ammonia as described in 1991, 52, 7) but instead can occur in an aprotic solvent such as tetrahydrofuran at high temperatures, for example. After completion of the reaction of ammonia with perfluoroalkylsulfonyl fluoride, the reaction proceeds in an aprotic solvent at -100 to -50 ° C, in particular at about -78 ° C, and the amine obtained is an alkali metal salt, preferably Converted to sodium salt. This experiment shows that, as is known in the literature, the reaction does not have to be carried out in alcoholic solutions, but instead the reaction with alkali metal hydroxides, preferably sodium hydroxide, can be made in a simple manner in aqueous solution. The compound of formula III can then be obtained in a simple manner by heating the alkali metal perfluoroalkylsulfonylamino salt in the presence of bis (trimethylsilyl) amine.

Subsequently, the compound according to formula (III) and α, ω-perfluoroalkanebis (sulfonyl fluoride) of formula (VIII) are subjected to simple heating to 40 to 70 캜, preferably to 65 to 70 캜 in aprotic solvent. By reacting the compound of formula IV, ie, Na [R _F -SO ₂ -N-SO _2- (CF ₂ ) _n -SO ₂ F] in high yield. Thus, such sodium [trifluoromethylsulfonyl-α, ω-perfluoroalkane-bis (sulfonyl fluoride) amide] is obtained in 90% yield. Suitable solvents for this reaction include 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, tetrahydrofuran or other cyclic ethers. The reaction is preferably carried out using tetrahydrofuran.

According to methods known from the literature, novel lithium compounds of formula V can be prepared from compounds of formula IV as described above. The inventors have found that the yield by the reaction of the compound of formula IV with the compound of formula III decreases as the chain length of α, ω-perfluoroalkane-bis (sulfonylfluoride) increases. After purifying and isolating the dilithium bisimide of formula V with n equal to 1, the yield is about 60%, while the corresponding bisimides with n equal 3 are obtained in only about 40% yield.

In particular, the compound of formula IV is prepared in an aprotic solvent selected from the group consisting of cyclic ethers, preferably pyran (corresponding to (±) -3-methyltetrahydropyran) at 100 to 110 ° C. Is used in an excess of 10 to 20%). Treatment with a mineral acid solution, preferably a solution consisting of aqueous hydrochloric acid in diethyl ether, provides a compound of formula

{R _F SO ₂ NH-SO _2- (CF ₂ ) _n -SO ₂ -HNSO ₂ R _F }

Where

n is 1, 2 or 3.

After purification, preferably by sublimation, the compound is converted into the corresponding dipotassium salt using an alkaline solution comprising aqueous potassium ions, preferably a potassium hydroxide solution, followed by LiCl, LiI and LiBr. Dilithium bisimide of Formula (V) is prepared by metathesis in an aprotic organic solvent such as tetrahydrofuran or 1,3-dioxolane with a lithium halide selected from the group consisting of lithium chloride, preferably lithium chloride.

In addition, the process according to the invention is novel perfluoroalkane-1-sulfonyl (perfluoroalkylsulfonyl) imide-n-sulfonyl-bis- (perfluoroalkylsulphur) as can be seen from the above reaction scheme. PONYL) METHINIDE AND METHOD FOR MANUFACTURING DILITHIMIDE IMIDE MAINIDE OF A COMPOSITION OF THE COMPOUND VI.

To prepare the compound, in a nonpolar aprotic solvent selected from the group consisting of tetrahydrofuran and 2-methyltetrahydrofuran, butyllithium in a solvent such as cyclohexane, n-hexane or other cyclic or bicyclic hydrocarbons or Bis (perfluoroalkylsulfonyl) methane is polar dilithiated at −10 to + 30 ° C., preferably 10 to 20 ° C. with methyllithium. A) reacting an equal amount of the compound of formula IV in 0 to 50 ° C., preferably 20 to 30 ° C., in an aprotic solvent selected from the group consisting of cyclic ethers, in particular tetrahydrofuran, b) then with ether Treatment with a mineral acid, in particular hydrochloric acid, in an organic solvent selected from the group consisting of diethyl ether or dibutyl ether, c) purification according to generally known methods, in particular by distillation, d) purification, preferably A novel metathesis of the mixed composition of formula (VI) is further metathesized with an alkaline cesium salt selected from the group consisting of CsOH and Cs ₂ CO ₃ , preferably cesium carbonate, regenerated by recrystallization, and e) further metathesis with lithium halides. One dilithium imide methide may be prepared. After purification, the desired product is obtained in a yield of about 25-35%.

As already indicated in the procedure of Scheme 1, the invention also relates to a process for preparing dialkali imide sulfonates, in particular the dilithium imide sulfonates of the formula (VII). Experiments have shown that these compounds can be prepared by saponifying the corresponding monovalent anions of Formula IV. For this purpose, it is possible to use the alkaline lithium salt is selected from the group consisting of aqueous solution of LiOH ₂ · H ₂ O and Li ₂ CO _3. Preferably, the reaction is carried out with a lithium hydroxide solution, specifically, monovalent anions in an aqueous solution are introduced as an initial input, and an alkaline lithium salt is added in 1.5-fold molar amount. Saponification is carried out at elevated temperatures, especially at boiling temperatures. If necessary, activated carbon can be added to the reaction solution to remove impurities. In a simple process, water can be removed after filtration to provide the reaction product, which can be salinified to produce the dilithium salt. The obtained saponification reaction product is placed in an aprotic solvent selected from the group consisting of ether tetrahydrofuran and 1,3-dioxolane, preferably tetrahydrofuran and used to dissolve the aprotic organic solvent, preferably the saponification product. It is mixed with the lithium halide dissolved in the same solvent as the molar amount thereof 1.5 times in the same solvent and stirred briefly at about 20 to 40 ° C, preferably at room temperature. The sodium halide formed is precipitated and can be removed by separation in a simple manner, such as by filtration or other methods known to those skilled in the art. After removal of the solvent, preferably by vacuum distillation, the desired dialaliimide sulfonate is obtained as a solid in a yield of at least 98%.

According to formula (I), the present invention also relates to symmetric bismetanides represented by the following formula (X) and crosslinked by fluorinated alkane chains and a process for their preparation:

M ₂ [(F ₃ CSO ₂ ) ₂ C-SO _2- (CF ₂ ) _n -SO ₂ C (SO ₂ CF ₃ ) ₂ ]

Where

M, n and R _F have the above meanings.

The experiment shows that the compound can be prepared by a simple procedure as shown in Scheme 2 using examples of the corresponding lithium salts.

Procedure of Scheme 2

Bis (perfluoroalkylsulfonyl) methane is placed in an aprotic solvent selected from the group consisting of cyclic ethers, preferably tetrahydrofuran, butyllithium prepared in a known manner and dissolved in a hydrocarbon such as cyclohexane, Lithiation is performed with alkyllithium such as methyllithium. Alternatively, the reaction can be carried out similarly using alkyl-Mg compounds. This lithiation reaction can be carried out at a temperature of 0 to 50 ℃, preferably 10 to 25 ℃. Thereafter, it is reacted with α, ω-perfluoroalkanesi (sulfonyl fluoride) of the above-mentioned formula VIII, wherein n may have the specified meaning. In this reaction the starting materials are used in molar ratios of 1: 0.3 to 1: 0.5. The reaction is carried out at 10-50 ° C. in cyclic ethers or bicyclic ethers, preferably tetrahydrofuran. Particularly excellent yields are obtained when using a temperature of 25 to 30 ° C.

The product obtained after treatment with a mineral acid solution, preferably hydrochloric acid solution, and also after removal of unreacted starting material is subjected to a corresponding solution using an aqueous cesium salt (which is alkaline in solution) selected from the group consisting of Cs ₂ CO ₃ and CsOH. To divalent anions and optionally subjected to initial purification, for example by recrystallization or by other methods known to those skilled in the art, to convert into organic solvents selected from the group consisting of diethyl ether and dibutyl ether, Treatment with an aqueous lithium solution converts to the desired salt, such as dilithium bismetanide of Formula Xa:

Formula Xa

Li ₂ [(R _F SO ₂ ) ₂ C-SO _2- (CF ₂ ) _n -SO ₂ -C (SO ₂ R _F ) ₂ ]

In particular, an equimolar amount of lithium hydroxide or its hydrate is used to release the dilithium bismetanide. In order to shift the reaction equilibrium, lithium hydroxide can also be used in excess.

The present invention therefore also relates to the sodium salts, potassium salts and cesium salts of the compounds represented by formula (I).

In particular, in the compounds according to the invention R _F is a fluorine-saturated radical, trifluoromethyl, pentafluoroethyl, i- and n-heptafluoropropyl, i-, n- and t-nonafluorobutylyl Can be.

In particular, the present invention relates to lithium salts of compounds represented by formula (I)

a) Li ₂ [(F ₃ CSO ₂ ) ₂ C-SO ₂ -CF ₂ -SO ₂ -C (SO ₂ CF ₃ ) ₂ ]

b) Li ₂ [(F ₃ CSO ₂ ) ₂ C-SO _2- (CF ₂ ) ₂ -SO ₂ -C (SO ₂ CF ₃ ) ₂ ]

c) Li ₂ [(F ₃ CSO ₂ ) ₂ C-SO _2- (CF ₂ ) ₃ -SO ₂ -C (SO ₂ CF ₃ ) ₂ ]

d) Li ₂ [F ₃ CSO ₂ N—SO ₂ —CF ₂ —C (SO ₂ CF ₃ ) ₂ ]

e) Li ₂ [F ₃ CSO ₂ N—SO ₂ — (CF ₂ ) ₂ C (SO ₂ CF ₃ ) ₂ ]

f) Li ₂ [F ₃ CSO ₂ N-SO _2- (CF ₂ ) ₃ -C (SO ₂ CF ₃ ) ₂ ]

g) Li ₂ [F ₃ CSO ₂ N-SO ₂ -CF ₂ -SO ₂ -N-SO ₂ CF ₃ ]

h) Li ₂ [F ₃ CSO ₂ N-SO _2- (CF ₂ ) ₂ SO ₂ -N-SO ₂ CF ₃ ]

i) Li ₂ [F ₃ CSO ₂ N-SO _2- (CF ₂ ) ₃ SO ₂ -N-SO ₂ CF ₃ ]

j) Li ₂ [F ₃ CSO ₂ N-SO ₂ -CF ₂ -SO ₃ ]

l) Li ₂ [F ₃ CSO ₂ N—SO ₂ — (CF ₂ ) ₂ SO ₃ ]

m) Li ₂ [F ₃ CSO ₂ N—SO ₂ — (CF ₂ ) ₃ SO ₃ ]

We found that the new compounds are extremely stable. For example, dry storage at a temperature of about 100 ° C. produces no decomposition at all. It discolors only at temperatures significantly higher than 200 ° C, indicating decomposition. However, even when stored in a solution such as, for example, an organic solvent such as tetrahydrofuran or acetonitrile, no change in color or degradation product was detected after storage for several weeks. Without other reasons, the novel compounds according to the invention are very stable as conductive salts in non-aqueous electrolytes for secondary lithium batteries.

In addition to the organolithium salts, the electrolyte comprising a compound according to the invention contains at least one non-aqueous organic solvent and optionally further additives. More specific details regarding such electrolytes, their composition and mode of operation of the secondary lithium battery are known to those skilled in the art. The compounds according to the invention can be used entirely similarly to the lithium compounds known for these uses. In this regard, the compounds according to the invention likewise exhibit particularly high stability. Corresponding battery cells exhibit excellent characteristics in terms of capacity, voltage invariance, and non-limiting operability over an average number of charge-discharge cycles.

In a cyclic voltammetric experiment in which aluminum is used as a working electrode, paired with a lithium electrode, the new dilithium bismetamide, in particular, showed very good conductivity in an aprotic solvent. In addition, the compound is stable in decomposition reactions while reducing the corrosion tendency of the aluminum current collector. In particular, these salts have a surface passivating or protective effect on aluminum. The compounds of formula (I) according to the invention can be used as conductive salts in both primary and secondary cells and thus can act as surface active salts in the electrolyte.

As mentioned above, the lithium salts described above are particularly suitable for use as conductive salts in electrolytes. In particular, the advantageous properties of these salts in this regard depend on the lithium content in the salts prepared. Of the lithium conductive salts mentioned heretofore, the dilithium imide sulfonate represented by the formula (VII) has the highest lithium content, ie, the lithium content of 3.91%. In addition, these salts can be prepared in very good yields according to the methods described herein. For example, saponification and subsequent metathesis proceed almost quantitatively. However, even the compounds represented by the formula (IV) used in the preparation of the conductive salts are obtained in a yield of 90% or more so that the preparation method of these conductive salts basically lowers the loss of starting material very much.

Lithium Content of Various Lithium Conductive Salts compound Li content (%) Li (PF ₆ ) 4.57 Li [N (SO ₃ CF ₃ ) ₂ ] 2.42 Li [C (SO ₃ CF ₃ ) ₃ ] 1.66 Li ₂ [F ₃ CSO ₂ N-SO ₂ -CF ₂ -SO ₃ ] (VIIa) 3.91 Li ₂ [F ₃ CSO ₂ N-SO ₂ -CF ₂ -SO ₂ -NSO ₂ CF ₃ ] (Va) 2.86 Li ₂ [F ₃ CSO ₂ N-SO ₂ -CF ₂ -SO ₂ -C (SO ₂ CF ₃ ) ₂ ] (VIa) 2.25

The following examples are provided to illustrate the invention and to aid its understanding, but do not limit the claimed subject matter to the examples given the generally valid teachings of the detailed description.

Example 1

Trifluoromethylsulfonylamide (F ₃ CSO ₂ NH ₂ )

Cool a 500 ml three-necked flask with a composite coil condenser (-78 ° C.) and an internal thermometer to -78 ° C., condense the anhydrous ammonia introduced through the gas inlet to a volume of 70 ml, and THF 200-250 ml Was slowly added dropwise. After cooling the THF / NH ₃ solution back to −78 ° C., 68 g (0.45 mol) of trifluoromethanesulfonyl fluoride (prepared according to J. Chem. Soc. (1956) 17) were about 2 Introduced through a gas inlet tube over time. During the high exothermic reaction, the ammonium fluoride formed precipitated, and some of the resulting ammonium amide precipitated. After the reaction was completed, the suspension was warmed to room temperature to evaporate the remaining ammonia. The precipitate was filtered off by suction and the remaining colorless solution was concentrated on a rotary evaporator. The product of the roughness is purified by sublimation at high vacuum.

Yield: 62.8 g (0.42 mol) or 93% (M = 149.09 g / mol) (CH ₂ F ₃ NO ₂ S)

Melting point: 118 ° C. (ignition temperature: 119 ° C.) [48; GRAMSTADT AND HAZELDINE]

Boiling Point: 60 to 70 ° C (0.01torr)

¹ H-NMR (CD ₃ CN, 500.13 MHz, 20% by weight), δ = 6.24 (b)

¹³ C-NMR (CD ₃ CN, 125.76 MHz, 20 wt%), δ = 120.94 (quat, ¹ J _CF = 319.0 Hz)

¹⁹ F-NMR (CD ₃ CN, External C ₆ F ₆ , 470.59 MHz, 20 wt%), δ = -80.89 (s)

IR (KBr pellet): γ = 3388 (s), 3277 (s), 1523 (s), 1360 (vs), 1235 (w), 1191 (vs), 1154 (w), 1043 (w), 955 ( w), 931 (mb), 564 (m), 490 (mb)

MS (EI, 70 eV, 35 ° C.)

m / e = 150 (2%, M + H ⁺ ), 133 (19%, F ₃ C-SO ₂ ⁺ ), 80 (100%, SO ₂ -NH ₂ ⁺ ), 69 (100%, CF ₃ ⁺ ), 64 (60%, SO ₂ ⁺ ), 48 (28%, SO ⁺ ), and other fragments

Example 2

Sodium Trifluoromethylsulfonylamide (Na [F ₃ CSO ₂ NH])

A suspension of 149 g (1.0 mol) of sublimated trifluoromethanesulfonylamide in 300 ml of water was carefully mixed with 40 g (1.0 mol) of sodium hydroxide, during which a clear colorless solution was formed. After stirring for 30 minutes, the solvent was removed under aqueous pressure and the remaining colorless residue was dried at 80 ° C. in high vacuum.

Yield: 170.12 g (0.99 mol) or 99% yield (CHF ₃ NNaO ₂ S) (171.O7 g / mol)

Calculation: C 7.02%, Na 13.45%

Obtained: C 7.05%, Na: 13.43%

IR (KBr pellet): γ = 3348 (s), 3295 (s), 3287 (s), 1295 (st), 1275 (st), 1250 (vs), 1178 (vs), 1089 (m), 1069 ( m), 998 (s), 639 (m), 618 (m), 574 (m), 513 (m), 483 (m)

Example 3

Sodium trifluoromethylsulfonyltrimethylsilylamide (Na [F ₃ CSO ₂ NSiMe ₃ ])

A solution of 42.8 g (250 mmol) of sodium trifluoromethanesulfonylamide in 800 ml of hexamethyldisilazane (HMDS) was refluxed (about 2 hours) until no release of ammonia was observed anymore. The solvent was then removed under aqueous pressure and the remaining hydrolysis-sensitive colorless residue was dried at 80-90 ° C.

Yield: 60.0 g (247 mmol) or 99% (M = 243.26 g / mol) (C ₄ H ₉ F ₃ NNaO ₂ SSi)

¹ H-NMR (CD ₃ CN, 500.13 MHz, 20% by weight) δ = 0.04 (s)

¹³ C-NMR (CD ₃ CN, 125.76 MHz, 20% by weight) δ = 2.25 (s), 122.64 (quat, ¹ J _CF = 324.6 Hz)

¹⁹ F-NMR (CD ₃ CN, External C ₆ F ₆ , 470.59 MHz, 20% by weight) δ = -78.23 (s)

²⁹ Si-NMR (CD ₃ CN, 99.36 MHz, 20% by weight) δ = −5.82 (s)

IR (KBr pellet): γ = 2960 (m), 2903 (w), 1277 (s), 1251 (vs), 1231 (vs), 1205 (vs), 1171 (s), 1145 (s), 1059 ( vs), 989 (m), 840 (vs), 762 (m), 730 (w), 712 (m), 692 (w), 620 (s), 579 (m), 548 (w), 523 ( w), 489 (w), 483 (w), 476 (w), 471 (w), 462 (w), 427 (w).

Example 4

Sodium perfluoroalkane-1-fluorosulfonyl-N-trifluoromethylsulfonylimide (Na [F ₃ CSO ₂ -N-SO _2- (CF ₂ ) _n -SO ₂ F], n is 1 To 3)

To a solution of 60.0 g (247 mmol) of sodium trifluoromethylsulfonyltrimethylsilylamide (Na [F ₃ CSO ₂ -N-SiMe ₃ ]) in 100 mL of tetrahydrofuran, the corresponding 1, n-alkane-bis (sul 250 mmol) was added dropwise. After stirring under reflux for 4 hours, the solvent was removed and the slightly yellowish colorless residue was dried at 60-70 ° C. in high vacuum.

Sodium perfluoroalkane-1-fluorosulfonyl-n-trifluoromethylsulfonylimide (Na [F ₃ CSO ₂ -N-SO _2- (CF ₂ ) _n -SO ₂ F], n is 1 To 3) n m _{starting material} (g) Yield (g) M _product (g / mol) Experimental formula One 54.5 88.9g or 98% 367.19 C ₂ F ₆ NNaO ₆ S ₃ 2 65.7 100.0g or 98% 417.19 C ₃ F ₉ NNaO ₆ S ₃ 3 78.1 113.1 g or 98% 467.20 C ₄ F ₁₀ NNaO ₆ S ₃

Na [F ₃ CSO ₂ -N-SO ₂ -CF ₂ SO ₂ F]

¹⁹ F-NMR (CD ₃ CN, 75.4 MHz, 20% by weight): δ = -96.81 (s, 2F), -78.40 (s, 3F), 46.04 (s, 1F)

Na [F ₃ CSO ₂ -N-SO _2- (CF ₂ ) ₂ SO ₂ F]

¹⁹ F-NMR (CD ₃ CN, 75.4 MHz, 20% by weight): δ = -110.80 (d, ³ J _FF = 7.1 Hz, 2F), -104.32 (d, ³ J _FF = 5.6 Hz, 2F),- 78.53 (s, 3F), 46.23 (t, ³ J _FF = 6.8 Hz, 1F)

Na [F ₃ CSO ₂ -N-SO _2- (CF ₂ ) ₃ SO ₂ F]

¹⁹ F-NMR (CD ₃ CN, 75.4 MHz, 20% by weight): δ = -117.26 (t, ³ J _FF = 3.7 Hz, 2F), -111.95 (t, ³ J _FF = 13.1 Hz, 2F),- 105.73 (t, ³ J _FF = 11.3 Hz, 2F), -78.57 (s, 3F), 46.68 (t, ³ J _FF = 6.8 Hz, 1F)

Example 5

Di-potassium perfluoroalkane-1, N-bis [sulfonyl (trifluoromethylsulfonyl) imide] (K ₂ [F ₃ CSO ₂ -N-SO _2- (CF ₂ ) _n -SO _2- N-SO ₂ CF ₃ ], n is 1 to 3)

A solution of 60.0 g (247 mmol) of Na [F ₃ CSO ₂ NSiMe] in 150 ml of pyran was mixed with the corresponding Na [F ₃ CSO ₂ N—SO ₂ — (CF ₂ ) _n —SO ₂ F] 188 mmol. The pale yellow to brown solution was then refluxed for 5 hours. The solvent was removed under aqueous pressure and the remaining yellow residue was dissolved in 600-700 mL of 3M hydrochloric acid and stirred for 4 hours. The solution was then extracted four times with 150 ml of diethyl ether each time. The ether phases were combined and concentrated under gentle conditions. The unreacted trifluoromethanesulfonamide was then sublimed from the remaining oil. 100-150 ml of water was added to the sublimation bottom, filtered through granular activated carbon, and neutralized with potassium hydroxide. After boiling with activated carbon and filtered, the water was removed under aqueous pressure. The colorless solid was recrystallized from about 300-400 ml of isopropanol. After filtration the crystals were dried in high vacuum at 70 ° C.

Dipotassium perfluoroalkane-1, n-bis [sulfonyl (trifluoromethylsulfonyl) imide (K ₂ [F ₃ CSO ₂ -N-SO _2- (CF ₂ ) _n -SO ₂ -N- SO ₂ CF ₃ ], n is 1 to 3) n m _{starting material} (g) Yield (g) M _product (g / mol) Experimental formula One 69.0 71.5g or 69% 550.47 C ₃ F ₈ K ₂ N ₂ O ₈ S ₄ 2 78.4 66.6 g or 59% 600.47 C ₄ F ₁₀ K ₂ N ₂ O ₈ S ₄ 3 87.8 63.6 g or 52% 650.48 C ₅ F ₁₂ K ₂ O ₈ S ₄

Elemental Analysis (% Units) n Experimental formula C calculation C yield K calculated K yield One C ₃ F ₈ K ₂ N ₂ O ₈ S ₄ 6.55 6.61 14.21 14.29 2 C ₄ F ₁₀ K ₂ N ₂ O ₈ S ₄ 8.00 8.11 13.02 13.13 3 C ₅ F ₁₂ K ₂ O ₈ S ₄ 9.23 9.31 12.02 12.24

Example 6

Dilithium tetrafluoroethane-bis [sulfonyl (trifluoromethylsulfonyl) imide] (Li ₂ [F ₃ CSO ₂ -N-SO _2- (CF ₂ ) ₂ -SO ₂ -N-SO ₂ CF ₃ ]

A solution of 100.00 g (182 mmol) of K ₂ [F ₃ CSO ₂ -N-SO ₂ -CF ₂ -SO ₂ -N-SO ₂ CF ₃ ] in 100 ml of tetrahydrofuran was added 15.40 g of lithium chloride in 650 ml of tetrahydrofuran. Mixed with a solution of (364 mmol). After stirring for 30 minutes, the precipitate of potassium chloride is filtered off and THF is removed under aqueous pressure. The resulting colorless solid is dried at high vacuum (less than 0.1 torr) at about 80 ° C.

Yield: 85.5 g (178 mmol) or 98%

(C ₃ F ₈ Cl ₂ N ₂ O ₈ S ₄ ) m = 486.15 g / mol

Calculated: C 7.41%, Li 2.86%, K 0.00%

Obtained: C 7.43%, Li 2.84%, K <0.1%

Water content: <2000ppm

Decomposition Point:> 200 ℃

Example 7

Dicemium difluoromethane-sulfonyl (trifluoromethylsulfonyl) imide-N-sulfonyl-bis (trifluoromethyl-sulfonyl) methanide (Cs ₂ [F ₃ CSO ₂ N-SO _2- CF ₂ -SO ₂ -C (SO ₂ CF ₃ ) ₂ ])

To a solution of 70 g (250 mmol) of bis (trifluoromethylsulfonyl) methane in 150 ml tetrahydrofuran 260 ml of a 2M butyllithium solution in cyclohexane was added dropwise while the mixture was cooled with ice. During the dropwise addition, the temperature was maintained at 10 to 20 ° C., and then stirring was continued. 92 g (250 mmol) of Na [F ₃ CSO ₂ N—SO ₂ —CF ₂ —SO ₂ F] in 100 mL of THF are added dropwise at a temperature of 20 ° C., and the temperature is maintained at 25 to 30 ° C. as possible. The reaction solution is heated to 60 ° C. for 2 hours. The solvent mixture is then removed. The resulting solid is placed in 500 ml of 3M hydrochloric acid and stirred for about 4 hours. The solution is then extracted four times with 150 ml of diethyl ether each time. After the ether phases are combined and the solvent is removed, the unreacted starting material is distilled off. The product remaining at the bottom was dissolved in 500 ml of water and neutralized with about 33 g of cesium carbonate. The cesium salt precipitated during the process is boiled and dissolved. The solution was then treated with activated carbon, heated for 30 minutes and then filtered. If necessary, the crystallized cesium salt was recrystallized again using water.

Yield: 69.1 g (80 mmol) or 32% (M = 869.15 g / mol) (C ₅ Cs ₂ F ₁₁ NO ₁₀ S ₅ )

¹³ C-NMR (CD ₃ CN, 125.8 MHz) δ = 86.14 (s, C (SO ₂ CF ₃ ) ₂ ), 119.54 (t, ¹ J _CF = 329.9 Hz, CF ₂ ), 120.02 (qua, ¹ J _CF = 320.5Hz, NSO ₂ CF ₃ ), 120.40 (C (SO ₂ CF ₃ ) ₂ )

¹⁹ F-NMR (CD ₃ CN, 470.6 MHz, External C ₆ F ₆ ): δ = -99.09 (s, 2F), -78.43 (s, 3F), -75.22 (s, 6F)

Example 8

Dilithium difluoromethane-sulfonyl (trifluoromethylsulfonyl) imide-N-sulfonyl-bis (trifluoromethyl-sulfonyl) methanide (Li ₂ [F ₃ CSO ₂ N-SO _2- CF ₂ -C (SO ₂ CF ₃ ) ₂ ])

A solution of 100.00 g (115 mmol) of Cs ₂ [F ₃ CSO ₂ -N-SO ₂ -CF ₂ -C (SO ₂ CF ₃ ) ₂ ] in 100 mL of THF was dissolved in 9.75 g (230 mmol) of LiCl in 400 mL of tetrahydrofuran. Mixed with solution. After stirring for 30 minutes, the CsCl precipitate was filtered off and tetrahydrofuran was removed under aqueous pressure. The resulting solid was dried at high vacuum (less than 0.1 torr) at about 80 ° C.

Yield: 69.56 g (113 mmol) or 98%

(C ₅ F ₁₁ Li ₂ NO ₁₀ S ₅ ) M = 617.22 g / mol

Calculations: C 9.73%, Li 2.25%, Cs 0.00%

Obtained: C 9.75%, Li 2.23%, Cs <0.1%

Water content: <2000ppm

Decomposition Point:> 200 ℃

Example 9

Dilithium difluoromethane-sulfonyl (trifluoromethylsulfonyl) imide-N-sulfonate (Li ₂ [F ₃ CSO ₂ N-SO ₂ -CF ₂ SO ₃ ])

A solution of 91.8 g (250 mmol) of Na ₂ [F ₃ CSO ₂ N—SO ₂ —CF ₂ —SO ₃ ] in 250 mL of water was mixed with 21.0 g (500 mmol) of lithium hydroxide monohydrate. If necessary, in the presence of activated carbon, the suspension was boiled for 1 hour, cooled to room temperature, filtered and the water removed under aqueous pressure. The colorless solid was dried and then dissolved in 250 ml of tetrahydrofuran. It was mixed with a solution of 10.6 g (250 mmol) of LiCl in 450 ml of tetrahydrofuran. After stirring for 30 minutes, the precipitated NaCl is filtered off and tetrahydrofuran is removed under aqueous pressure. The resulting solids are dried at 80 ° C. under high vacuum (<0.1torr).

Yield: 87.0 g (245 mmol) or 98% (C ₂ F ₅ Li ₂ NO ₇ S ₃ ) (M = 355.08 g / mol)

Calculated: C 6.77%, Li 3.91%, Na 0.00%

Yield: C 6.81%, Li 3.95%, Na <0.1%

Water content: <2000ppm

Decomposition Point:> 200 ℃

¹³ C-NMR (CD ₃ CN, 125.8 MHz), δ = 119.82 (t, ¹ J _CF = 319.1 Hz),

¹⁹ F-NMR (CD ₃ CN, 470.6 MHz, external C ₆ F ₆ ), δ = -105.38 (s, 2F), -78.64 (s, 2F),

Electrochemical research

Stability against reduction

Li ₂ [(F ₃ CSO ₂ ) ₂ -SO ₂ -in test solvent mixture EC / DMC (1: 1; water content of about 10-20 ppm) and EC / DEC (1: 1; water content of about 10-20 ppm) The (CF ₂ ) ₃ -SO ₂ -C (SO ₂ CF ₃ ) ₂ ] salt has excellent stability to lithium. The base current cycle voltage diagram (FIG. 1) does not show any signal suggestive of cathodic decomposition.

Stability against oxidation

a) oxidation at inert platinum electrodes

The dissolution potential of divalent methoxide was measured at 5.3 V independently from the solvent mixture for Li / Li ⁺ . This indicates that decomposition of the solvent may actually be involved. 2 shows a voltage diagram when measured using an EC / DMC mixture as a solvent.

b) oxidation on aluminum electrodes

Unlike in the case of monovalent sulfonyl derivatives, the salts studied effectively stabilized the aluminum surface (FIG. 3). In no case dissolution of aluminum was observed.

Cycle experiment

Cycle characteristics were measured potentiometrically (FIG. 3, Table 5) and electrostatistically (Tables 6 and 7) using the cycle amphoteric method. The results are within the range of salts already studied.

1 is Li ₂ [(F ₃ CSO ₂ ) ₂ C-SO _2- (CF ₂ ) ₃ -SO ₂ -C (SO ₂ CF ₃ ) ₂ ] (0.58 mol) in DMC / EC (mdcv 279) under the following conditions: The analysis of the ground current cycle current voltage measurement, carried out using), is shown graphically:

Measuring device: three-electrode placement

Working electrode: V2A alloy steel; Electrode Area: 0.503cm2

Counter electrode: lithium

Reference electrode: lithium

Cycle count: 5

Ramp rate: 20mV / s

FIG. 2 shows Li ₂ [(F ₃ CSO ₂ ) ₂ C-SO _2- (CF ₂ ) ₃ -SO ₂ -C (SO ₂ CF ₃ ) ₂ ] (0.58 mol) in DMC / EC (mdcv 285) under the following conditions: The anode stability range for the platinum (electrode area 0.071 cm 2) of the electrolyte according to the present invention is shown in the form of a graph using the following example:

Measuring device: three-electrode placement

Working electrode: V2A alloy steel; Electrode Area: 0.503cm2

Counter electrode: lithium

Reference electrode: lithium

Cycle count: 5

Tilt rate: 10 mV / s

FIG. 3 shows Li ₂ [(F ₃ CSO ₂ ) ₂ C—SO ₂ — (CF ₂ ) ₃ —SO ₂ —C (SO ₂ CF ₃ ) ₂ ] (0.58 mol) in DMC / EC (mdcv 280) under the following conditions: Cycle deposition experiments using) show lithium deposition in graphical form:

Measuring device: three-electrode placement

Working electrode: V2A alloy steel; Electrode Area: 0.503cm2

Counter electrode: lithium

Reference electrode: lithium

Cycle count: 5

Tilt rate: 20 mV / s

4 shows Li ₂ [(F ₃ CSO ₂ ) ₂ C-SO _2- (CF ₂ ) ₃ -SO ₂ -C (SO ₂ CF ₃ ) in DMC / MC (mdcv 284) on aluminum (electrode area 0.583 cm ₂ ). ₂ ] (0.58 mol) positive electrode stability.

FIG. 5 shows Li ₂ [(F ₃ CSO ₂ ) ₂ C-SO _2- (CF ₂ ) ₃ -SO ₂ -C () at various temperatures in a DEC / EC (1: 1) (x _ec = 0.5724) solvent mixture. SO ₂ CF ₃ ) ₂ ] shows the non-conductivity coefficient κ (m, T) as a function of concentration.

Comparison of Cycle Yields Li ₂ [(F ₃ CSO ₂ ) ₂ C-SO _2- (CF ₂ ) ₃ -SO ₂ -C (SO ₂ CF ₃ ) ₂ ] DMC / EC (0.58 mol) Li ₂ [(F ₃ CSO ₂ ) ₂ C-SO _2- (CF ₂ ) ₃ -SO ₂ -C (SO ₂ CF ₃ ) ₂ ] DEC / EC (0.61 mol) 1 cycle 65.8% 80.7% 2 cycles 68.1% 79.1% 3 cycles 70.2% 81.7% 4 cycles 72.8% 84.4% 5 cycles 75.5% 87.2% Average 70.5% 82.6%

Comparison of Cycle Yields Li ₂ [(F ₃ CSO ₂ ) ₂ C-SO _2- (CF ₂ ) ₃ -SO ₂ -C (SO ₂ CF ₃ ) ₂ ] DMC / EC (0.58 mol) Li ₂ [(F ₃ CSO ₂ ) ₂ C-SO _2- (CF ₂ ) ₃ -SO ₂ -C (SO ₂ CF ₃ ) ₂ ] DMC / EC (0.61 mol) yield(%) 26.4 22.7 Measuring device: two-electrode batching electrode: V2A alloy steel; Electrode area: 0.503 cm 2 Counter electrode: Li-plating Current density: i _Plating = 1 mA / cm 2 Stripping current density: i _Strip = 1 mA / cm 2 Plating Charge: Q _Plating = 100 mC / cm 2 Potential at blocking: 2000 mV for Li / Li ⁺

Comparison of Cycle Yields Li ₂ [(F ₃ CSO ₂ ) ₂ C-SO _2- (CF ₂ ) ₃ -SO ₂ -C (SO ₂ CF ₃ ) ₂ ] DMC / EC (0.58 mol) Li ₂ [(F ₃ CSO ₂ ) ₂ C-SO _2- (CF ₂ ) ₃ -SO ₂ -C (SO ₂ CF ₃ ) ₂ ] DMC / EC (0.61 mol) Cycle count 0.62 1.49 yield(%) 11.3 24.8 Measuring device: two-electrode batching electrode: V2A alloy steel; Electrode area: 0.503 cm 2 Counter electrode: Li-plated Current density: i _Plating = 1 mA / cm 2 Stripping current density: i _Strip = 1 mA / cm 2 Basic charge: Q _o = 4000 mC / cm 2 Cycle charge: Q _z = 1000 mC / cm 2 Dislocation: 2000mV against Li / Li ⁺

Claims (13)

A compound of formula (I) M ₂ [R ₁ -SO _2- (CF ₂ ) _n -SO ₂ -R] Where R is C (SO ₂ R _F ) ₂ , N (SO ₂ R _F ) or O, R ₁ is C (SO ₂ R _F ) ₂ or N (SO ₂ R _F ), R and R ₁ are independent of each other, R _F is (C _x F _{2x + 1} ), M is a counter ion selected from the group consisting of Li, Na, K, Cs, Rb, Be _1/2 , Mg _1/2 , Sr _1/2 and Ba _1/2 , n is 1, 2 or 3, x is 1, 2, 3 or 4. The method of claim 1, A compound of formula I, wherein M is Li. The method of claim 1, A compound of formula I, wherein M is Na, K or Cs as intermediate for preparing a compound of formula I according to claim 1 wherein M is Li. The method according to claim 1 or 2, A compound selected from a) to m) a) Li ₂ [(F ₃ CSO ₂ ) ₂ C-SO ₂ -CF ₂ -SO ₂ -C (SO ₂ CF ₃ ) ₂ ] b) Li ₂ [(F ₃ CSO ₂ ) ₂ C-SO _2- (CF ₂ ) ₂ -SO ₂ -C (SO ₂ CF ₃ ) ₂ ] c) Li ₂ [(F ₃ CSO ₂ ) ₂ C-SO _2- (CF ₂ ) ₃ -SO ₂ -C (SO ₂ CF ₃ ) ₂ ] d) Li ₂ [F ₃ CSO ₂ N—SO ₂ —CF ₂ —C (SO ₂ CF ₃ ) ₂ ] e) Li ₂ [F ₃ CSO ₂ N-SO _2- (CF ₂ ) ₂ -C (SO ₂ CF ₃ ) ₂ ] f) Li ₂ [F ₃ CSO ₂ N-SO _2- (CF ₂ ) ₃ -C (SO ₂ CF ₃ ) ₂ ] g) Li ₂ [F ₃ CSO ₂ N-SO ₂ -CF ₂ -SO ₂ -N-SO ₂ CF ₃ ] h) Li ₂ [F ₃ CSO ₂ N-SO _2- (CF ₂ ) ₂ SO ₂ -N-SO ₂ CF ₃ ] i) Li ₂ [F ₃ CSO ₂ N-SO _2- (CF ₂ ) ₃ SO ₂ -N-SO ₂ CF ₃ ] j) Li ₂ [F ₃ CSO ₂ N-SO ₂ -CF ₂ -SO ₃ ] l) Li ₂ [F ₃ CSO ₂ N—SO ₂ — (CF ₂ ) ₂ SO ₃ ] m) Li ₂ [F ₃ CSO ₂ N—SO ₂ — (CF ₂ ) ₃ SO ₃ ]. The method according to claim 1, 2 or 4, a) reacting perfluoroalkylsulfonyl fluoride with ammonia dissolved in an aprotic solvent, b) treating the obtained amine with sodium hydroxide dissolved in water to give the corresponding sodium salt, c) sodium salt Is reacted with (Me ₃ Si) ₂ NH under heating to provide sodium perfluoroalkylsulfonyltrimethylsilylamide of formula III, and d) converting the compound of formula III to 1, N-perfluoroalkane-bis ( Sulfonyl fluoride) to give sodium perfluoroalkane-1-fluorosulfonyl-N-perfluoroalkyl-sulfonylimide represented by Formula IV, and e) a compound of Formula IV is represented by Formula III Reacted with sodium perfluoroalkylsulfonyltrimethylsilylamide in sequential reactions in acidic ether solution, aqueous KOH, and then metathesis to convert to dilithium bisimide of formula (V), or f) reacting one equivalent of the compound of formula IV with dilithiated bis (perfluoroalkylsulfonyl) methane and suitably post-treating and metathesizing the obtained reaction product to prepare the dilithium imidemethane of formula VI, or Or g) reacting a compound of formula IV with an alkaline lithium salt and metathesizing it with a lithium halide to obtain perfluoroalkane-1-sulfonyl- (perfluoroalkylsulfonyl) imide-N-sulfonate of formula VII A process for preparing a compound of formula I, characterized in that Formula III Na (R _F SO ₂ NSiMe ₃ ) Formula IV Na [R _F SO ₂ NSO ₂ (CF ₂ ) _n SO ₂ F] Formula V Li ₂ (R _F SO ₂ NSO _2- (CF ₂ ) _n -SO ₂ NSO ₂ R _F ) Formula VI Li ₂ (R _F SO ₂ NSO _2- (CF ₂ ) _n -SO ₂ C (SO ₂ R _F ) ₂ ) Formula VII Li ₂ [R _F SO ₂ NSO ₂ (CF ₂ ) _n SO ₃ ] Where R _F is (C _x F _{2x + 1} ), x is 1, 2, 3 or 4, n is 1, 2 or 3. The method according to claim 1, 2 or 4, a) bis (perfluoroalkylsulfonyl) methane is lithiated at 0-50 ° C., preferably 10-25 ° C. in an aprotic organic solvent, preferably tetrahydrofuran, selected from the group consisting of cyclic ethers Reacting with α, ω-perfluoroalkanebis (sulfonyl fluoride) of formula VIII at a molar ratio of 1: 0.3 to 1: 0.5, at a temperature of 0 to 50 ° C, preferably 20 to 30 ° C, Then b) reacted first in the mine solution, the solvent and unreacted starting material are separated off, converted to the corresponding divalent anion using alkaline cesium salt in solution, and purified as necessary, and c) di The compound of formula (Xa) was first treated with a mineral acid, preferably hydrochloric acid, in an organic solvent selected from the group consisting of ethyl ether and dibutyl ether, followed by reaction in an aqueous lithium hydroxide solution. Lithium bis, comprising a step of switching to the meta arsenide, R ₁ and R are the same _{(C (SO 2 R F)} 2) with a compound of formula I having the meanings of: Formula VIII FO ₂ S- (CF ₂ ) _n -SO ₂ F Formula Xa Li ₂ [(R _F SO ₂ ) ₂ C-SO _2- (CF ₂ ) _n -SO ₂ -C (SO ₂ R _F ) ₂ ]. Use of a compound of formula (I) according to any one of claims 1 to 4 in an electrolyte system. Use of a compound of formula (I) according to claim 1 in an electrochemical cell. Use of a compound of formula (I) according to any one of claims 1 to 4 in a primary battery. Use of a compound of formula (I) according to any one of claims 1 to 4 in a secondary battery. Use of a compound of formula (I) according to any of claims 1 to 4 as a conductive salt of a lithium battery. An electrolyte for a lithium battery comprising the lithium compound of formula (I) according to any one of claims 1 to 4. A secondary lithium battery comprising the electrolyte according to claim 12.