| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a crystalline nanometric LiFePO<SB>4</SB>. <P>SOLUTION: The invention relates to lithium secondary batteries and more specifically to positive electrode materials operating at potentials greater than 2.8 V with respect to that of Li<SP>+</SP>/Li in nonaqueous electrochemical cells. In particular, the invention relates to crystalline nanometric carbon-free olivine-type LiFePO<SB>4</SB>powders having enhanced electrochemical properties. A direct precipitation process is described for producing crystalline LiFePO<SB>4</SB>powder, the process comprising the steps of: providing a water-based mixture having at a pH 6-10, containing a water-miscible boiling point elevation additive, and Li<SP>(I)</SP>, Fe<SP>(II)</SP>and P<SP>(V)</SP>as precursor components; heating the water-based mixture to a temperature less than or equal to its boiling point at atmospheric pressure, thereby precipitating the crystalline LiFePO<SB>4</SB>powder. <P>COPYRIGHT: (C)2010,JPO&INPIT |
