SciELO - Scientific Electronic Library Online

 
vol.23 número7Complexation behavior in aqueous edta sol-gel systems for the synthesis of YBa2Cu3O7-x high-temperature superconductorsUnsynchronized resonance of covalent bonds in the superconducting state índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Journal of the Brazilian Chemical Society

versión impresa ISSN 0103-5053

Resumen

XU, Yang et al. Preparation and electrochemical properties of homogeneous carbon-coated LiFe0.9Mn0.1PO4 as cathode material for lithium-ion batteries. J. Braz. Chem. Soc. [online]. 2012, vol.23, n.7, pp. 1298-1304. ISSN 0103-5053.  http://dx.doi.org/10.1590/S0103-50532012000700014.

Homogeneous carbon-coated LiFe0.9Mn0.1PO4 cathode material was synthesized by one-step solid-state reaction using glucose as carbon source. Powder X-ray diffractometry (XRD), transmission electron microscopy (TEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic measurements were employed to characterize the samples. Mn-doping and carbon co-modification did not affect the olivine structure of LiFePO4, but improved its kinetics in terms of capacity delivery, polarization and rate capability. When compared with the undoped LiFePO4/C, the LiFe0.9Mn0.1PO4/C sample presented good size distribution - around 100-200 nm - and better electrochemical performance. At current rates of 0.1, 1.0, 3.0 and 10.0 C (C = 170 mA g-1), the LiFe0.9Mn0.1PO4/C electrode delivered discharge capacities of 154.1, 138.8, 120.0 and 94.0 mA h g-1, respectively. Results obtained by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) indicated that the polarization and charge transfer resistance of the sample were greatly decreased by Mn-doping.

Palabras llave : Mn-doping; LiFePO4; cathode material; lithium-ion batteries.

        · resumen en Portugués     · texto en Inglés     · pdf en Inglés