The invention relates to an aprotic polymer/molten salt ternary mixture solvent and to a corresponding quaternary mixture additionally comprising an ionic conducting salt, which are prepared by mixing the constituents of the mixture. These mixtures are advantageously used in the preparation of electrochemical membranes, electrochemical systems and of electrochromic systems. The invention also relates to electrochemical and electrochromic systems obtained hereby that exhibit, in particular, excellent electrochemical properties at low temperatures.

The invention relates to an aprotic polymer/molten salt ternary mixture solvent and to a corresponding quaternary mixture additionally comprising an ionic conducting salt, which are prepared by mixing the constituents of the mixture. These mixtures are advantageously used in the preparation of electrochemical membranes, electrochemical systems and of electrochromic systems. The invention also relates to electrochemical and electrochromic systems obtained hereby that exhibit, in particular, excellent electrochemical properties at low temperatures.

The invention relates to a fluorination process for producing fluorinated compounds.The process consists in reacting a compound (I) corresponding to the formula ##STR00001## with an ionic fluoride of a monovalent cation. M represents H, an alkali metal, a quaternary phosphonium group or a quaternary ammonium group. Y represents SO.sub.2 and m is 1, or else Y is PO and m is 2. Z represents CR.sup.2, N or P. R.sup.1 represents an electron-withdrawing group which has a Hammet .sigma..sub.P parameter of greater than 0.4. R.sup.2 represents a carbonaceous and/or electron-withdrawing group. X represents a halogen other than a fluorine.The fluorinated compounds obtained are of use in particular as electrolytes in lithium batteries.

Method of synthesis for a material made of particles having a core and a coating and/or being connected to each other by carbon cross-linking, the core of these particles containing at least one compound of formula Li.sub.xM.sub.1-yM'.sub.y(XO.sub.4).sub.n, in which x, y and n are numbers such as 0.ltoreq.x.ltoreq.2, 0.ltoreq.y.ltoreq.0.6 and 1.ltoreq.n.ltoreq.1.5, M is a transition metal, M' is an element with fixed valency, and the synthesis is carried out by reaction and bringing into equilibrium the mixture of precursors, with a reducing gaseous atmosphere, in such a way as to bring the transition metal or metals to the desired valency level, the synthesis being carried out in the presence of a source of carbon called carbon conductor, which is subjected to pyrolysis. The materials obtained have excellent electrical conductivity, as well as very improved chemical activity.

The present invention is concerned with a protective coating with current applied on a metallic collector of an electrode. The protective coating comprises a mineral binder vitreous or partly vitreous and optionally an electronic conduction additive. This coating is applied in the form of a solution or dispersion on the collector of the electrode and dried, so that it coats and protects at least part of the surface of the metal of the collector to prevent the formation of passivation films generated by active species produced by other components of the generator.