Abstract
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.
Original language | English |
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Pages (from-to) | 921-926 |
Number of pages | 6 |
Journal | Bulletin of the Korean Chemical Society |
Volume | 32 |
Issue number | 3 |
DOIs | |
Publication status | Published - 2011 Mar 20 |
Keywords
- Binding energy
- Doping
- LiFePO
- Rate performance
- XPS
ASJC Scopus subject areas
- General Chemistry