کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1491271 | 1510727 | 2008 | 11 صفحه PDF | دانلود رایگان |

Nano-sized particles of spinel LiMn2O4 and LiCrxMn2−xO4 (x = Cr; 0.00–0.40) have been synthesized using phthalic acid as chelating agent for the first time by sol–gel method. When compared to solid-state synthesis method, the sol–gel route reduces heating time of synthesize and to obtain particles of uniform surface morphology. The synthesized samples were characterized through thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). SEM images of the parent compounds show nanospherical grains of LiMn2O4 when compared to chromium-doped ones. XRD patterns of LiMn2O4 ascertain amorphous nature and for high calcined LiCrxMn2−xO4 single phase highly crystalline patterns were obtained. TEM images of the parent and chromium-doped spinel particles depict individual grain morphology with well-separated grain boundaries. LiCr0.10Mn1.90O4 excels in discharge and cycling behaviour and offer higher columbic efficiency, when compared to un-doped LiMn2O4. Cyclic voltammograms of LiMn2O4 and LiCrxMn2−xO4 exhibit oxidation and reduction peaks corresponding to Mn3+/Mn4+ and Cr3+/Cr4+.
Journal: Materials Research Bulletin - Volume 43, Issues 8–9, 4 August–4 September 2008, Pages 2119–2129