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Phase Transition of Bare and Coated Li[sub x]CoO[sub 2] (x=0.4 and 0.24) at 300°C

2005; Institute of Physics; Volume: 152; Issue: 9 Linguagem: Inglês

10.1149/1.1979193

1945-7111

Youngil Lee, Min Gyu Kim, Ji-Suk Kim, Yoojin Kim, Jaephil Cho,

Semiconductor materials and interfaces

The phase transitions of the bare and -coated delithiated ( and 0.24) according to the coating concentration (thickness) after heat-treatment at was investigated using nuclear magnetic resonance and X-ray absorption spectra. It was found that the bare and coated predominantly decomposed into spinel or phases depending on the charging voltage. As the charging voltage was increased from , the bare and -coated decomposed into the phase while the -coated sample decomposed into the phase. The improvement in the thermal stability of the -coated , compared to the bare and -coated samples, could be explained by the dominant local formation of the phase over the phase.