کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1286824 | 1497955 | 2015 | 7 صفحه PDF | دانلود رایگان |
• Thin films of Co3O4 have been synthesized using MOCVD technique at 450 °C and 500 °C.
• At 500 °C, columnar structures are found; spherical agglomerates are seen at 450 °C.
• Comparative study between these films made as anode in Li ion batteries.
In this study, thin films of cobalt oxide (Co3O4) have been grown by the metal-organic chemical vapor deposition (MOCVD) technique on stainless steel substrate at two preferred temperatures (450 °C and 500 °C), using cobalt acetylacetonate dihydrate as precursor. Spherical as well as columnar microstructures of Co3O4 have been observed under controlled growth conditions. Further investigations reveal these films are phase-pure, well crystallized and carbon-free. High-resolution TEM analysis confirms that each columnar structure is a continuous stack of minute crystals. Comparative study between these Co3O4 films grown at 450 °C and 500 °C has been carried out for their application as negative electrodes in Li-ion batteries. Our method of electrode fabrication leads to a coating of active material directly on current collector without any use of external additives. A high specific capacity of 1168 micro Ah cm−2 μm−1 has been measured reproducibly for the film deposited at 500°C with columnar morphology. Further, high rate capability is observed when cycled at different current densities. The Co3O4 electrode with columnar structure has a specific capacity 38% higher than the electrode with spherical microstructure (grown at 450°C). Impedance measurements on the Co3O4 electrode grown at 500 °C also carried out to study the kinetics of the electrode process.
Journal: Journal of Power Sources - Volume 277, 1 March 2015, Pages 198–204