Synthesis of crystalline nanometric LiFeMPO4
US8066916B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Nov 19, 2007 |
| Grant date | Nov 29, 2011 |
| Priority date | — |
| Expiry date | Nov 19, 2027 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P70/50
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
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 LiFe1-xMxPO4 powder with M is Co and/or Mn, and 0<x<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(I), Fe(II), P(V), and Co(II) and/or Mn(II) as precursor components;—heating said water-based mixture to a temperature less than or equal to its boiling point at atmospheric pressure, thereby precipitating crystalline LiFe1-xMxPO4 powder. 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…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.