Arkema France

Rémy Teissier

Wissam Rached

Philippe Bonnet

Grégory Schmidt

Gregory Schmidt

Georges Martino-Gauchi

A method for drying and purifying a lithium bis(fluorosulfonyl)imide salt. Also, a method for producing a lithium bis(fluorosulfonyl)imide salt which is then dried and purified by the method. Further, a composition containing lithium bis(fluorosulfonyl)imide salt having a water content by mass of between 5 and 45 ppm. And, the use of the composition C in Li-ion batteries.

Method for drying and purifying lithium bis(fluorosulfonyl)imide salt

The present invention relates to a method for drying and purifying a lithium bis(fluorosulfonyl)imide salt in solution in an organic solvent S1, said method comprising the following steps: a) adding deionised water to dissolve and extract the lithium bis(fluorosulfonyl)imide salt, forming an aqueous solution of said salt; b) extracting the lithium bis(fluorosulfonyl)imide salt from said aqueous solution, using an organic solvent S2, said step being repeated at least once; c) concentrating the lithium bis(fluorosulfonyl)imide salt by evaporating said organic solvent S2 and the water, in a short-path thin-film evaporator, under the following conditions: temperature of 30&#xb0; C. to 95&#xb0; C., pressure of 10mbar abs to 5 mbar abs, residence time no longer than 15 min; and d) optionally crystallising the lithium bis(fluorosulfonyl)imide salt. The present invention likewise relates to a composition made of lithium bis(fluorosulfonyl)imide salt, and the uses thereof in Li-ion batteries.

Method for drying and purifying LiFSI

The present invention relates to a method for preparing a polyinsaturated perfluorinated compound B from a polyinsaturated perhalogenated compound D having the formula CX, in which X is independently selected from one of the halogens, F, Cl, Br or I, provided at least one X is not fluorine; n is the number of carbon atoms and is at least higher than or equal to 4, m is the number of double carbon-carbon bonds and is higher than or equal to 2, wherein the method comprises a step in which compound D is fluorinated in the presence of a fluorinating agent of general formula AF, in which A is hydrogen, an alkali metal or an alkaline earth metal, and p is 1 or 2, and in the presence of an aprotic organic polar solvent; the method being carried out with a molar ratio of AFto compound D of less than 1.45*2(n&#x2212;m+1).

Method for preparing polyunsaturated perfluorinated compounds

The present invention relates to a method for preparing hexafluorobutadiene comprising the following steps: (a) hydrodechlorinating hexachlorobutadiene to form a first stream comprising 1,2,3,4-tetrachlorobutadiene and optionally unreacted hexachlorobutadiene; (b) fluorinating the first stream comprising 1,2,3,4-tetrachlorobutadiene obtained in step (a) to form a second stream comprising 1,1,2,3,4,4-hexafluorobutane, (c) dehydrogenating the second stream comprising 1,1,2,3,4,4-hexafluorobutane to form a third stream comprising hexafluorobutadiene.

Method for preparing hexafluorobutadiene

The invention concerns a continuous method for preparing ethyl lactate by esterifying lactic acid with ethanol, in the presence of a catalyst which comprises reacting said lactic acid with ethanol in an initial ethanol/lactic acid mol ratio not less than 2.5, in the presence of a catalyst, at a reflux of the reaction medium of about 100&#xb0; C. under absolute pressure ranging between 1.5 to 3 bars. Said method is characterized in that it comprises continuously extracting from the esterification reaction medium a near-azeotropic water/ethanol gas mixture: than dehydrating said gas mixture directly using molecular sieves, than recuperating from said dehydration an ethanol gas stream capable of being recycled to the esterification reaction medium and a flow consisting of water and ethanol which is subjected to distillation wherefrom is obtained water and an azeotropic water/ethanol mixture which is injected into the distillation column head of the gas mixture extracted from the esterification reaction medium; then in continuously extracting crude ethyl lactate which is subjected to purification wherefrom are obtained high purity ethyl lactate and heavy products.

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Francheville, France

Rémy Teissier