Centre National De La Recherche Scientifique

Umicore

Pierre Gibot

Christian Masquelier

Michèle Van Thournout

Stephane Levasseur

Stéphane Levasseur

Jean-Marie Tarascon

Philippe Carlach

The invention relates to crystalline nanometric olivine-type LiFeMPOpowder with M being Co and/or Mn, and 0&#x2266;x&#x2266;1, with small particle size and narrow particle size distribution. A direct precipitation process is described, comprising the steps of: providing a water-based mixture having at a pH between 6 and 10, containing a dipolar aprotic additive, and Li, Fe, P, and Coand/or Mnas precursor components; heating said water-based mixture to a temperature less than or equal to its boiling point at atmospheric pressure, thereby precipitating crystalline LiFeMPOpowder. An extremely fine particle size is obtained of about 80 nm for Mn and 275 nm for Co, both with a narrow distribution.

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The invention relates to active materials for the manufacture of Li-based batteries. A crystalline nanometric powdered material with formula Li(M, M')PO, in particular LiFePO(O&#x2266;x&#x2266;1), is disclosed, exhibiting single phase Li insertion/extraction mechanism at room temperature when used as positive electrode material in Li-based batteries. Compared to current LiFePO, the novel material results in smooth, sloping charge/discharge voltage curve greatly simplifying the monitoring of the state of charge of the batteries. The coexistence of mixed valence states for Fe (i.e. FeVFe) is believed to increase the electronic conductivity in the room temperature single phase LiFePOmaterial, compared to state of the art two-phase materials. This, together with the nanometric size of the particles and their sharp monomodal size distribution, contributes to the exceptional high-rate capability demonstrated in batteries.

Room temperature single phase Li insertion/extraction material for use in Li-based battery

The present invention relates to crystalline nanometric olivine-type LiFeMnPOpowder with 0&#x3c;x&#x3c;1, with small particle size and narrow particle size distribution. The fine particle size is believed to account for excellent high-drain properties, while minimizing the need for conductive additives. The narrow distribution facilitates the electrode manufacturing process and ensures a homogeneous current distribution within the battery.

The present invention relates to lithium secondary batteries and more specifically to positive electrode materials operating at potentials greater than 2.8 V vs. Li/Li in non-aqueous electrochemical cells. In particular, the invention relates to crystalline nanometric olivine-type LiFeMPOpowder with M is Co and/or Mn, and 0&#x3c;x&#x3c;1, with small particle size and narrow particle size distribution. A direct precipitation process is described, comprising the steps of:&#x2014;providing a water-based mixture having at a pH between 6 and 10, containing a dipolar aprotic additive, and Li, Fe, P, and Coand/or Mnas precursor components;&#x2014;heating said water-based mixture to a temperature less than or equal to its boiling point at atmospheric pressure, thereby precipitating crystalline LiFeMPOpowder. An extremely fine particle size is obtained of about 80 nm for Mn and 275 nm for Co, both with a narrow distribution. The fine particle size is believed to accounts for excellent high-drain properties, while minimizing the need for conductive additives. The narrow distribution facilitates the electrode manufacturing process and ensures a homogeneous current distribution within the battery.

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Amiens, France

Pierre Gibot