Commissariat &#xc0; L'&#xc9;nergie Atomique Et Aux &#xc9;nergies Alternatives

Commissariat a L'energie Atomique

Centre National De La Recherche Scientifique

Nathalie Herlin-Boime

Olivier Sublemontier

Yann Leconte

Dominique Porterat

Axelle Quinsac

Carole Bourbon

Jean-François Colin

David Peralta

Benoit Guizard

Francois Tenegal

François Tenegal

Willy Porcher

Cédric Haon

John Alper

Marc Brestaz

Frederic Lacour

Frédéric Lacour

Romuald Dez

Florent Boismain

Antoine Desrues

Jérémie Fondard

Séverine Jouanneau Si Larbi

Cécile Reynaud

Benoît Guizard

A method for preparing a positive electrode active material for a lithium battery consisting of a lithiated oxide comprising titanium and optionally one or more other metal elements comprising the following successive steps: a) a step of forming a precipitate comprising titanium and the optional other metal element(s) by contacting a titanium coordination complex and, if necessary, at least one salt of the other metal element(s) with an aqueous medium; b) a step of recovering the precipitate thus formed; c) a step of calcining the precipitate in the presence of a lithium source.

Method for preparing a positive electrode active material of the lithiated metal oxide type comprising titanium

Provided is method for synthesising core-shell nanoparticles by laser pyrolysis. The method may include a) conveying together a gaseous mixture including a silicon precursor and a germanium precursor in a reaction zone of a first chamber of a reactor, and b) emitting a first laser beam at the level of the reaction zone for carrying out a laser pyrolysis of the mixture, the steps making it possible to obtain nanoparticles having a core made of a silicon- and germanium-based alloy and a silicon shell.

Method for synthesising core-shell silicon-germanium nanoparticles by laser pyrolysis, method for producing an electrode for a lithium battery and associated electrode

A device for synthesising core-shell nanoparticles by laser pyrolysis is provided. The device includes a reactor having a first chamber for synthesising the core, which is provided with an inlet for a core precursor; a second chamber for synthesising the shell, which is provided with an inlet for a shell precursor; and at least one communication channel between the two chambers for transmitting the core of the nanoparticles to be formed in the first chamber towards the second chamber. The device also includes an optical device for illuminating each of the two chambers, and at least one laser capable of emitting a laser beam intended to interact with the precursors in order to form the core and the shell.

Device for synthesising core-shell nanoparticles by laser pyrolysis and associated method

A method for producing an electrode comprising a core-shell nanocomposite material of which the core is made from silicon and the shell from carbon is provided. The method includes A) synthesising the nanocomposite material by pyrolysing a silicon core to form a core and then pyrolysing a a carbon shell precursor to form a carbon shell around the core, wherein the quantities of silicon and carbon precursor are injected in a proportion such that the mass percentage of carbon in the nanocomposite material is greater than or equal to 45%; B) dispersing the nanocomposite material synthesised in step A) in a solvent to form an ink; C) applying this ink to a support intended to form an electricity collector; D) eliminating the solvent from the ink applied to the support in step C) to obtain the electrode; E) pressing or calendaring the electrode.

Method for producing an electrode for a lithium accumulator and associated electrode

The invention relates to the synthesis of silicon-containing nanoparticles by laser pyrolysis. For this purpose: a precursor (SIH) containing the element silicon is conveyed, by a transport fluid (He), into a pyrolysis reactor (REAC); laser radiation (LAS) is applied, in the reactor, to a mixture that the transport fluid and the precursor form; and silicon-containing nanoparticles (nP) are recovered at the exit of the reactor. In particular, the power of the laser radiation is controlled. Furthermore, the effective pulse duration is controlled within a laser firing period. Typically, for a power greater than 500 watts and a pulse duration greater than 40% of a laser firing period, nanoparticles having a crystalline structure with a size of less than or of the order of one nanometer are obtained at a rate greater than or of the order of 80 milligrams per hour. Under optimum conditions, a record rate of greater than 740 milligrams per hour was able to be obtained.

Synthesis of silicon nanocrystals by laser pyrolysis

A system and process for production of nanometric or sub-micrometric powders in continuous flux under the action of laser pyrolysis in at least one interaction zone between a beam emitted by a laser and a flux of reagents emitted by an injector, in which the laser is followed by optical means for distributing the energy of the beam emitted by the latter according to an axis perpendicular to the axis of each flux of reagents, in an elongated cross-section having adjustable dimensions at the level of this at least one interaction zone.

Production of nanometric or sub-micrometric powders in continuous flux

The invention relates to the synthesis of silicon-containing nanoparticles by laser pyrolysis. For this purpose: a precursor (SiH) containing the element silicon is conveyed, by a transport fluid (He), into a pyrolysis reactor (REAC); laser radiation (LAS) is applied, in the reactor, to a mixture that the transport fluid and the precursor form; and silicon-containing nanoparticles (nP) are recovered at the exit of the reactor. In particular, the power of the laser radiation is controlled. Furthermore, the effective pulse duration is controlled within a laser firing period. Typically, for a power greater than 500 watts and a pulse duration greater than 40% of a laser firing period, nanoparticles having a crystalline structure with a size of less than or of the order of one nanometer are obtained at a rate greater than or of the order of 80 milligrams per hour. Under optimum conditions, a record rate of greater than 740 milligrams per hour was able to be obtained.

The invention provides a method of synthesizing a Si/C/N/E/F/G/O multielement nanopowder that is directly suitable for sintering, E, F, and G representing three distinct metallic elements other than Si, and at least one of a, b, and c being non-zero. The nanopowder is obtained by laser pyrolysis of an aerosol comprising at least one metal precursor, hexamethyldisilazane SiCNHused as the sole solvent for said at least one metal precursor, and silane SiH. Each grain of the resulting nanopowder contains all of the elements Si, C, N, E, F, G, and O, and the chemical composition of the nanopowder in terms of equivalent stoichiometric compounds is such that its free carbon content is less than 2% by weight and its SiOcontent is less than 10% by weight. The use of this nanopowder for fabricating a SiN/SiC composite ceramic.

Sinterable nanopowder ceramic material and method for synthesis thereof

Growing community of inventors

Orsay, France

Nathalie Herlin-Boime