Publications (2)1.49 Total impact
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Article: Performance and capacity fading reason of LiMn2O4/graphite batteries after storing at high temperature
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ABSTRACT: Spinel LiMn2O4 was synthesized by a solid-state method. A 204468-size battery was fabricated and stored at 55°C. The structure and morphology of the LiMn2O4 cathode were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM) technique. Energy dispersive spectroscopy (EDS) was used to analyze the surface component of the carbon anode. The discharge capacities of LiMn2O4 stored for 0, 24, 48, and 96 h are 106, 98, 96, and 92 mAh·g−1, respectively. The cyclic performance is improved after storage. The capacity retentions of LiMn2O4 stored for 0, 24, 48, and 96 h are 83.8%, 85.8%, 86.9%, and 88.6% after 180 cycles. The intensity of all the LiMn2O4 diffraction peaks is weakened. Mn is detected from the carbon electrode when the battery is stored for 96 h. Cyclic voltammograms and electrochemical impedance spectroscopy (EIS) were used to examine the surface state of the electrode after storage. The results show that the resistance and polarization of LiMn2O4/electrolyte is increased after storage, which is responsible for the fading of capacity.Rare Metals 05/2012; 28(4):322-327. · 0.59 Impact Factor -
Article: Sol-gel synthesis and photoluminescence properties of BaSO4/Y2O3:Eu3+ core-shell submicrospheres
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ABSTRACT: Europium-doped nanocrystalline Y2O3 phosphor layers were coated on the surface of preformed submicron BaSO4 spheres via the sol-gel process. The obtained BaSO4/Y2O3:Eu3+ core-shell phosphors were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and photoluminescence spectra. The results showed that the obtained BaSO4/Y2O3:Eu3+ core-shell phosphors consisted of well-dispersed submicron spherical particles with narrow size distribution and non-agglomeration. TEM and EDS results showed that BaSO4 particles were well coated with the shell of Y2O3:Eu3+. XRD result demonstrated that no reaction occurred between the BaSO4 cores and the Y2O3:Eu3+ shells even after annealing at 1200 °C. The BaSO4/Y2O3:Eu3+ core-shell particles showed a red emission corresponding to 5D0–7F2 of Eu3+ under the excitation of ultraviolet.Journal of Rare Earths 27(6):891-894. · 0.90 Impact Factor
