This study investigates a root cause of the improved rate performance of LiFePO4 after metal doping to Fesites. This is because the metal doped LiFePO4/C maintains its initial capacity at higher C-rates than undoped one. Using LiFePO4/C and doped LiFe0.97M 0.03PO4/C (M=Al3+, Cr3+, Zr 4+), which are synthesized by a mechanochemical process followed by one-step heat treatment, the Li content before and after chemical delithiation in the LiFePO4/C and the binding energy are compared using atomic absorption spectroscopy (AAS) and X-ray photoelectron spectroscopy (XPS). The results from AAS and XPS indicate that the low Li content of the metal doped LiFePO4/C after chemical delithiation is attributed to the low binding energy induced by weak Li-O interactions. The improved capacity retention of the doped LiFePO4/C at high discharge rates is, therefore, achieved by relatively low binding energy between Li and O ions, which leads to fast Li diffusivity.
|Number of pages||6|
|Journal||Bulletin of the Korean Chemical Society|
|Publication status||Published - 2011 Mar 20|
- Binding energy
- Rate performance
ASJC Scopus subject areas