Abstract: The invention relates to an electrochemical lithium accumulator comprising a stack of at least two electrochemical cells, each cell being separated from its adjacent cell by a current-collecting substrate, a first face of this substrate being occupied by an electrode of a cell while a second substrate face opposite to the first is occupied by an electrode of its adjacent cell, each cell comprising a positive electrode and a negative electrode separated by an electrolyte, characterized in that the electrolyte comprises a lithium polysulfide additive.

Abstract: The invention relates to an electrochemical lithium accumulator comprising at least one first electrochemical cell and at least one second electrochemical cell separated from each other by a current-collecting substrate, which substrate supports on a first face, an electrode of said first electrochemical cell, and on its second face opposite to said first face, an electrode of opposite sign of said second electrochemical cell, each cell comprising a positive electrode and a negative electrode separated by an electrolyte, characterized inter alio in that said current-collecting substrate is in copper or in copper alloy.

Abstract: The invention relates to lithium-bearing iron phosphate in the form of micrometric mixed aggregates of nanometric particles, to an electrode and cell resulting therefrom and to the method for manufacturing same, which is characterized by a nanomilling step.

Abstract: A film made of a fluorinated polymer of the polyvinylidene fluoride type having suitable properties for use as a lithium storage battery separator is produced using a phase inversion technique in which a solution containing the fluorinated polymer is brought into the presence of an atmosphere laden with water vapor to precipitate the fluorinated polymer. The fluorinated polymer can be precipitated by placing the support on which the solution is deposited, in which the fluorinated polymer has been previously dissolved, in an enclosure containing an atmosphere laden with water vapor and thermostatically regulated to a temperature comprised between 30° C. and 70° C. The relative humidity content during precipitation of the fluorinated polymer is advantageously between about 60% and about 98%.

Abstract: A lamellar-type oxide, in particular used as active material of a positive electrode for a lithium battery and to a method for synthesizing such an oxide. The oxides are used as active materials for the positive electrode of a lithium battery. With such oxides, the specific capacity of a lithium battery is improved and stabilized on cycling.

Abstract: A method of synthesis of a metal fluorophosphate having the following general formula (1): XaMb(PO4)cFd (1), in which: X is an alkaline metal selected among sodium (Na) and lithium (Li) or a mixture of said metals; M is a transition metal selected among the following elements: Co, Ni, Fe, Mn, V, Cu, Ti, Al, Cr, Mo, Nb or a combination of at least two of said metals, 0?a?5; 0.5?b?3; 0.5?c?3; and d is an integer equal to 1, 2 or 3. The method contains an electric-field-activated sintering process for a mixture (1) formed by at least one first phosphate-containing solid precursor and at least one second fluorine-containing solid precursor.

Abstract: A method for preparing a mixture of a powder of an electrode active compound and of a powder of an electron conducting compound, wherein the following successive steps are performed: a liquid medium is prepared containing the powder of the electrode active compound and the powder of the electron conducting compound; the liquid medium containing the powder of the electrode active compound and the powder of the electron conducting compound is subjected to the action of high energy ultrasonic waves; the liquid medium is removed; the mixture of the powder of the electrode active compound and of the powder of the electron conducting compound is collected. The thereby obtained mixture. An electrode comprising said mixture as an electrochemically active material. A cell comprising at least such an electrode, and an accumulator or battery comprising one or more of these cells.

Abstract: A method for producing a composite sulphur/carbon conductive material obtained solely from an initial sulphur and an initial carbon which includes the following successive steps between 50% and 90% by weight of initial sulphur and between 50% and 10% by weight of initial carbon having a specific surface smaller than or equal to 200 m2/g are placed in a reactor at atmospheric pressure, the sum of the proportions respectively of the initial sulphur and carbon attaining 100%, the reactor is hermetically sealed at atmospheric pressure, and the composite sulphur/carbon conductive material is formed, in powder form, by heat treatment by heating said reactor to a heating temperature comprised between 115° C. and 400° C., without external regulation of the pressure inside the reactor, and keeping said reactor at said heating temperature during a predetermined time.

Abstract: The invention relates to a positive electrode/electrolyte pair for lithium batteries operating at a voltage above 4.2 V versus Li+/Li. The electrolyte of the lithium battery used in the invention includes at least a first additive chosen from optionally substituted, cyclic or acyclic, carboxylic or dicarboxylic anhydrides and carboxylic or dicarboxylic acids, and mixtures thereof, and optionally a second additive which is a lithium salt, the total content of additive(s) being greater than or equal to 0.01% by weight and less than or equal to 30% by weight, relative to the total weight of electrolyte, and the positive electrode is made of a material having a spinel structure. The lithium batteries of the invention are applicable in particular in the field of portable equipment, such as telephones, computers, camcorders, cameras and tooling.

Abstract: A lamellar-type oxide, in particular used as active material of a positive electrode for a lithium battery and to a method for synthesizing such an oxide. The oxides are used as active materials for the positive electrode of a lithium battery. With such oxides, the specific capacity of a lithium battery is improved and stabilized on cycling.

Abstract: A compound containing titanium diphosphate TiP2O7 and carbon covering at least part of the surface of the TiP2O7 particles presents properties which make it suitable for use as active material of an electrode for a lithium storage battery. A compound of this kind is prepared more particularly by mixing at least one first precursor containing the titanium element with a +4 oxidation state, a phosphorus-based second precursor and an organic precursor containing the carbon element. The mixture then undergoes heat treatment at a temperature of between 500° C. and 800° C. in an inert atmosphere.

Abstract: A spinel structure compound of the formula LiNi0.4Mn1.6O4-?, wherein ?>0, has a lattice parameter of from 8.179 to 8.183 ?. The compound may be prepared by mixing carbonated precursors under stoichiometric conditions to produce a mixture, subjecting the mixture to a first heat treatment at a temperature of from 500 to 700° C., and then subjecting the mixture to one or more annealing treatments at a temperature of from 700 to 950° C., followed by cooling in a medium containing oxygen. The spinel structure compound may be used as an electrochemically active material in an electrode, for example an electrode of a battery.

Abstract: The LiMPO4 compound is synthesized by reacting a compound of general formula XMPO4, nH2O where X represents a radical selected from —NH4 and —H and M is a transition metal selected from Co, Ni and Mn, with a lithium source such as lithium nitrate, at a temperature lower than or equal to 350° C. The XMPO4, nH2O compound further exhibits a particular morphology in the form of platelets that is preserved during the reaction between the two precursors. The LiMPO4 compound thus synthesized is advantageously used as active material of an electrode for a lithium storage battery.

Abstract: A compound containing titanium diphosphate TiP2O7 and carbon covering at least part of the surface of the TiP2O7 particles presents properties which make it suitable for use as active material of an electrode for a lithium storage battery. A compound of this kind is prepared more particularly by mixing at least one first precursor containing the titanium element with a +4 oxidation state, a phosphorus-based second precursor and an organic precursor containing the carbon element. The mixture then undergoes heat treatment at a temperature of between 500° C. and 800° C. in an inert atmosphere.

Abstract: The invention relates to a material comprising carbon nanotubes, deposited at the surface of each of which is a substantially continuous film of nanoscale silicon particles, that can be used in negative electrodes for a lithium battery.

Abstract: This material or spinel structure compound has the formula LiyNi0.5?xMn1.5+xO4?? where: 0.9<y?1.1; 0<x?0.1; ?>0. Also, it has a lattice parameter of 8.167 to 8.190 ?, preferably from 8.179 to 8.183 ?.

Abstract: The state of charge of a Li-Ion storage battery comprising a positive electrode active material presenting a constant lithium insertion/extraction potential over most of the capacity operating range and titanium oxide TiO2 of bronze type structure as negative electrode active material can be easily monitored by simple reading of the operating voltage. The positive electrode active material is selected among LiNi0.5Mn1.5O4 and derivatives thereof.