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1 Materials Science Poland

1 2014

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Synthesis, effect of γ-ray and electrical conductivity of uranium doped nano LiMn2O4 spinels for applications as positive electrodes in Li-ion rechargeable batteries

El-Metwaly F G, Abou-Sekkina M. M, Saad F A, Khedr A. M.

Materials Science Poland

2014

Vol. 32, No. 4

571--577

LiMn2O4 is an attractive candidate cathode material for Li-ion rechargeable batteries, but it suffers from severe capacity fading, especially at higher temperature (55 ◦C) during charging/discharging processes. Recently, many attempts have been made to synthesize modified LiMn2O4. In this work, a new study on the synthesis of pure and U4+-doped nano lithium manganese oxide [LiMn2−xUxO4, (x = 0.00, 0.01, 0.03)] via solid-state method was introduced. The synthesized LiMn1.97U0.03O4 was irradiated by γ-radiation (10 and 30 kGy). The green samples and the resulting spinel products were characterized using thermogravimetric and differential thermal analysis (TG/DTA), X-ray diffraction (XRD), infrared (IR), and scanning electron microscopy (SEM) measurements. XRD and SEM studies revealed nano-sized particles in all prepared samples. Direct-current (DC) electrical conductivity measurements indicated that these samples are semiconductors and the activation energies decrease with increasing rare-earth U4+ content and γ-irradiation. ∆Ea equals to 0.304 eV for LiMn1.99U0.01O4, ∆Ea is 0.282 eV for LiMn1.97U0.03O4 and decreases to ∆Ea = 0.262 eV for γ-irradiated LiMn1.97U0.03O4 nano spinel. The data obtained for the investigated samples increase their attractiveness in modern electronic technology.