[摘要]：The Li1+xTi2-xFex(PO4)(3)/C series with 0 <= 5 <= 0.4 was prepared by a sol-gel method. XRD patterns showed a rhombohedral phase and minor contribution of an orthorhombic phase. The local environment of the phosphate structure was analyzed by P-31 MAS NMR spectroscopy. The electrochemical lithium insertion revealed two reversible regions for Fe3+/Fe2+ and Ti4+/Ti3+ reactions as confirmed by Fe-57 Mossbauer spectroscopy. Capacity values as large as 130 mA h g(-1) were recorded for Li1.2Ti1.8Fe0.2(PO4)(3)/C after 40 cycles. The drastic decrease in capacity observed for LiTi2(PO4)(3)/C cycled at C/2 was explained in terms of a lower kinetic response at the electrode-electrolyte interphase. |
