Patents by Inventor Frédéric Le Cras

Frédéric Le Cras has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20100330401
    Abstract: The lithium-ion microbattery comprises a positive electrode having a first Li+ ion storage capacity and a first thickness made from a first lithium insertion material, an electrolyte and a negative electrode having a second storage capacity and a second thickness made from a second insertion material. The thicknesses are such that the ratio of the first storage capacity over the second storage capacity is greater than or equal to 10 and lower than or equal to 1000. During the first charging of the micro-battery, the Li+ ions are inserted in the negative electrode and completely saturate the second insertion material. When initial charging is continued, they form a metallic lithium layer between the electrolyte and the lithium-saturated negative electrode by electroplating. During the subsequent charging and discharging cycles, only the metallic lithium layer participates in transfer of lithium ions.
    Type: Application
    Filed: June 18, 2010
    Publication date: December 30, 2010
    Applicant: COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
    Inventors: Sami Oukassi, Frédéric Le Cras, Steve Martin, Raphaël Salot
  • Patent number: 7776234
    Abstract: The present invention relates to a process for preparing composite materials comprising an electrode active compound of formula AaDdMmZzOoNnFf, such as an alkali metal ion, such as a lithium ion, insertion compound, and an electronically conducting compound, such as carbon, in which a homogeneous mixed precursor containing all the elements A, D, M, Z, O, N and F forming the electrode active compound and also one or more organic and/or organometallic compounds are thermally decomposed, in a short period of time, so as to obtain the composite material. These composite materials in particular find their application in devices containing said compounds and/or active materials, such as electrochemical devices and batteries, in particular lithium batteries.
    Type: Grant
    Filed: January 26, 2005
    Date of Patent: August 17, 2010
    Assignee: Commissariat a l'Energie Atomique
    Inventors: Gilles Gauthier, Frederic Le Cras, Helene Lignier, Jean-Louis Gabelle
  • Patent number: 7754384
    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.
    Type: Grant
    Filed: January 10, 2008
    Date of Patent: July 13, 2010
    Assignee: Commissariat A l'Energie Atomique
    Inventors: Sébastien Patoux, Frédéric Le Cras, Carole Bourbon, Séverine Jouanneau
  • Patent number: 7682596
    Abstract: A powdery compound selected from the group consisting of Li4Ti5O12 and its derivatives selected from the group consisting of Li4?xMxTi5O12 and Li4Ti5?yNyO12 (x and y between 0 and 0.2, M and N selected from the group consisting of Na, K, Mg, Nb, Al, Ni , Co, Zr, Cr, Mn, Fe, Cu, Zn, Si and Mo), used as active material of an electrode for a lithium storage battery, consists of unitary particles having a diameter not greater than 1 ?m and 10-50% volume agglomerated particles having a diameter not greater than 100 ?m wherein the agglomerated particles formed by agglomeration of said unitary particles. The method for producing such a compound preferably consists in grinding the synthesized oxide for a duration comprised between 24 hours and 48 hours in a planetary mill and in then performing thermal treatment at a temperature comprised between 450° C. and 600° C.
    Type: Grant
    Filed: August 8, 2005
    Date of Patent: March 23, 2010
    Assignee: Commissariat à l'Energie Atomique
    Inventors: Carole Bourbon, Séverine Jouanneau, Frédéric Le Cras, Hélène Lignier
  • Patent number: 7671568
    Abstract: The present invention relates to a method for charging a lithium-ion accumulator with a negative electrode at an operating potential larger than 0.5 volts relatively to the Li+/Li pair, which comprises a first charging step at a constant voltage between 2 volts and 5 volts.
    Type: Grant
    Filed: June 29, 2005
    Date of Patent: March 2, 2010
    Assignee: Commissariat a l'Energie Atomique
    Inventors: Sebastien Martinet, Frederic Le Cras, Dominique Perrin, Djamel Mourzagh
  • Publication number: 20100028676
    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.
    Type: Application
    Filed: March 12, 2008
    Publication date: February 4, 2010
    Applicant: COMMISSARIAT A L'ENERGIE ATOMIQUE
    Inventors: Sebastien Patoux, Carole Pagano, Carole Bourbon, Frederic Le Cras
  • Patent number: 7652907
    Abstract: A memory device including a stack of layers. At least one first active layer is based on a crystalline ionic and electronic conducting material capable of releasing and/or accepting at least one ionic species. At least one second active layer is based on a crystalline ionic and electronic conducting material capable of releasing and/or accepting the ionic species. The first active layer and the second active layer are based on a material that has a high potential variation for a low variation in the concentration of the ionic species. At least one layer forms an electrolyte between the first active layer and the second active layer, and is based on at least one ionic conducting and electronic insulating material. A measurement instrument is provided for measuring the electrochemical potential difference between the first active layer and the second active layer.
    Type: Grant
    Filed: August 21, 2007
    Date of Patent: January 26, 2010
    Assignee: Commissariat A l'Energie Atomique
    Inventors: Didier Bloch, Frederic Le Cras
  • Patent number: 7622224
    Abstract: A lithium storage cell comprises at least a first electrode comprising an active material wherein Li+ cations can be inserted, a second electrode and an electrolyte. The active material of the first electrode comprises a linear condensed compound comprising at least two tetrahedra, respectively of AO4 and A?O4 type, bonded by a common oxygen atom. A transition metal ion M2+ with a degree of oxidation of +2 selected from the group consisting of Ni2+, Co2+, Mn2+, Fe2+ and Ti2+ is inserted in the linear condensed compound, and the ratio between the number of Li+ cations able to be inserted in the active material and the number of transition metal ions M2+ is strictly greater than 1. A and A? are selected from the group consisting of P5+, Si4+, Al3+, S6+, Ge4+, B3+.
    Type: Grant
    Filed: November 30, 2004
    Date of Patent: November 24, 2009
    Assignee: Commissariat à l'Energie Atomique
    Inventors: Severine Si Larbi Jouanneau, Frederic Le Cras, Carole Bourbon, Gilles Gauthier
  • Publication number: 20090231907
    Abstract: A non-volatile electrochemical memory cell formed of a stack of thin films comprising at least one first active layer, suited to releasing and accepting, in a reversible manner, at least one ion species, at least one second active layer, suited to releasing and accepting said ion species, in a reversible manner, the active layers being based on materials having different compositions and electrochemical potential profiles.
    Type: Application
    Filed: February 26, 2009
    Publication date: September 17, 2009
    Applicant: COMMISSARIAT A L'ENERGIE ATOMIQUE
    Inventors: Didier Bloch, Carole Bourbon, Frederic Le Cras, Antoine Nowodzinski
  • Publication number: 20090130558
    Abstract: A material or compound is provided having a spinel structure and corresponding to the formula LiyNi0.5Mn1.5-xIVMnxIIIAzO4-d, where: 0.02?x?0.35; d>0; A is selected from the group comprising Na, K, Mg, Nb, Al, Ni, Co, Zr, Cr, Fe, Cu, Ti, Zn, Si and Mo; 0.8?y?1.2; 0?z?0.1; and has a mesh parameter of between 8.174 and 8.179 ?.
    Type: Application
    Filed: December 12, 2005
    Publication date: May 21, 2009
    Applicant: COMMISSARIAT A LENERGIE ATOMIQUE
    Inventors: Severine Jouanneau, Frederic Le Cras, Carole Bourbon, Helene Lignier
  • Patent number: 7529014
    Abstract: Lithium insertion compound having the following formula (I): Li?M?M1vM2wM3xM4yM5zB?(XO4??Z?)1??(I) M is selected from V2+, Mn2+, Fe2+, Co2+ and Ni2+; M1 is selected from Na+ and K+; M2 is selected from Mg2+, Zn2+, Cu2+, Ti2+, and Ca2+; M3 is selected from Al3+, Ti3+, Cr3+, Fe3+, Mn3+, Ga3+, and V3+; M4 is selected from Ti4+, Ge4+, Sn4+, V4+, and Zr4+; M5 is selected from V5+, Nb5+, and Ta5+; X is an element in oxidation state m, exclusively occupying a tetrahedral site and coordinated by oxygen or a halogen, which is selected from B3+, Al3+, V5+, Si4+, P5+, S6+, Ge4+ and mixtures thereof; Z is a halogen selected from F, Cl, Br and I; the coefficients ?, ?, v, w, x, y, z, ? and ? are all positive and satisfy the following equations: 0???2??(1); 1???2??(2); 0<???(3); 0???2??(3); 0???2??(4); ?+2?+3?+v+2w+3x+4y+5z+m=8????(5); and 0 < ? ? + v + w + x + y + z ? 0.1 , preferably, 0 < ? ? + v + w + x + y + z ? 0.05 . Methods for preparing these compounds.
    Type: Grant
    Filed: December 2, 2003
    Date of Patent: May 5, 2009
    Assignee: Commissariat a l'Energie Atomique
    Inventors: Sylvain Franger, Frédéric Le Cras, Carole Bourbon
  • Publication number: 20080280207
    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.
    Type: Application
    Filed: December 21, 2006
    Publication date: November 13, 2008
    Applicant: COMMISSARIAT A L'ENERGIE ATOMIQUE
    Inventors: Sebastien Patoux, Frederic Le Cras
  • Publication number: 20080272740
    Abstract: The present invention relates to a method for charging a lithium-ion accumulator with a negative electrode at an operating potential larger than 0.5 volts relatively to the Li+/Li pair, which comprises a first charging step at a constant voltage between 2 volts and 5 volts.
    Type: Application
    Filed: June 29, 2005
    Publication date: November 6, 2008
    Applicant: COMMISSARIAT A L'ENERGIE ATOMIQUE
    Inventors: Sebastien Martinet, Frederic Le Cras, Dominique Perrin, Djamel Mourzagh
  • Publication number: 20080113267
    Abstract: The present invention relates to a method of chemically modifying a lithium-based oxide comprising at least one transition metal, which comprises, in succession: a step of bringing said oxide into contact with an aqueous solution comprising phosphate ions; a step of separating said oxide from the aqueous solution; and a step of drying said oxide. Use of the modified lithium transition metal oxide as active positive electrode material for a lithium secondary battery.
    Type: Application
    Filed: February 10, 2006
    Publication date: May 15, 2008
    Inventors: Severine Jouanneau, Frederic Le Cras, Carole Bourbon
  • Publication number: 20080107968
    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 ?.
    Type: Application
    Filed: January 10, 2008
    Publication date: May 8, 2008
    Applicant: Commissariat A L'Energie Atomique
    Inventors: Sebastien Patoux, Frederic Le Cras, Carole Bourbon, Severine Jouanneau
  • Publication number: 20080031798
    Abstract: A powdery compound of mixed titanium lithium oxide, preferably used as active material of an electrode for a lithium storage battery, consists of particles having a diameter smaller than or equal to 1 ?m and of at least 10% by volume of grains having a diameter smaller than or equal to 100 ?m. It is formed by agglomeration of said particles. The method for producing such a compound preferably consists in grinding the synthesized oxide for a duration comprised between 24 hours and 48 hours in a planetary mill and in then performing thermal treatment at a temperature comprised between 450° C. and 600° C.
    Type: Application
    Filed: August 8, 2005
    Publication date: February 7, 2008
    Applicant: COMMISSARIAT A L'ENERGIE ATOMIQUE
    Inventors: Carole Bourbon, Severine Jouanneau, Frederic Le Cras, Helene Lignier
  • Patent number: 7326493
    Abstract: The subject of the present invention is a lithium electrochemical generator comprising two peripheral electrodes—one positive and the other negative—each comprising an electrically conductive substrate (13, 21) and an active layer (14, 20) that includes an active material, at least one bipolar electrode comprising a positive active layer (18) on a first electrically conductive substrate and a negative active layer (16) on a second electrically conductive substrate, the said substrates being fixed together and two separators (15, 19) flanking each bipolar electrode, in which generator the electrically conductive substrates of each bipolar electrode are made of identical or different materials chosen from aluminium and its alloys and the negative active material of the bipolar electrode prevents an aluminium alloy being obtained with the electrically conductive substrates, under the operating conditions of the storage battery.
    Type: Grant
    Filed: November 27, 2002
    Date of Patent: February 5, 2008
    Assignee: Commissariat a l'Energie Atomique
    Inventors: Sébastien Martinet, Frédéric Le Cras
  • Publication number: 20070292760
    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.
    Type: Application
    Filed: May 31, 2007
    Publication date: December 20, 2007
    Applicant: COMMISSARIAT A L'ENERGIE ATOMIQUE
    Inventors: Sebastien Patoux, Carole Bourbon, Frederic Le Cras
  • Publication number: 20070245546
    Abstract: The invention relates to a lithium battery, comprising at least one lithium intercalation compound, made up of crystallites and obtained by a production method, comprising at least the following steps: formation of a homogeneous mixture of at least one precursor for the lithium intercalation compound with a given adjunct, chemically stable with relation to crystallites and designed to limit the growth of crystallites or crystallite precursors during the formation thereof, thermal treatment of the homogeneous mixture for the synthesis of the lithium intercalation compound in the form of crystallites and to give a composite material comprising at least two phases formed respectively by the lithium intercalation compound and the adjunct and forming of the composite material to give said electrode. The invention further relates to an electrode obtained by said method and lithium battery comprising such an electrode.
    Type: Application
    Filed: July 21, 2005
    Publication date: October 25, 2007
    Applicant: COMMESSARIAT A L'ENERGIE ATOMIQUE
    Inventors: Frederic Le Cras, Sebastien Martinet, Carole Bourbon, Sebastien Launois
  • Publication number: 20070152185
    Abstract: The present invention relates to a process for preparing composite materials comprising an electrode active compound of formula AaDdMmZzOoNnFf, such as an alkali metal ion, such as a lithium ion, insertion compound, and an electronically conducting compound, such as carbon, in which a homogeneous mixed precursor containing all the elements A, D, M, Z, O, N and F forming the electrode active compound and also one or more organic and/or organometallic compounds are thermally decomposed, in a short period of time, so as to obtain the composite material. These composite materials in particular find their application in devices containing said compounds and/or active materials, such as electrochemical devices and batteries, in particular lithium batteries.
    Type: Application
    Filed: January 26, 2005
    Publication date: July 5, 2007
    Inventors: Gilles Gauthier, Frederic Le Cras, Helene Lignier, Jean-Louis Gabelle