Dependence of Al2O3 Coating Thickness and Annealing Conditions on Microstructural and Electrochemical Properties of LiCoO2 Film
Dependence of Al2O3 Coating Thickness and Annealing Conditions on Microstructural and Electrochemical Properties of LiCoO2 Film
- 주제(키워드) thin-film LiCoO2 , energy storage materials , coating , electrochemistry , scanning electron microscopy (SEM)
- 발행기관 대한금속·재료학회
- 발행년도 2010
- 총서유형 Journal
- UCI G704-000797.2010.16.1.003
- KCI ID ART001452187
- 본문언어 영어
초록/요약
We studied the dependence of Al2O3 coating thickness and annealing conditions on the surface morphology and electrochemical properties of Al2O3 coated LiCoO2 films. The optimum coating thickness allowing for the highest capacity retention was about 24 nm. A sample consisting of Al2O3 coated on annealed LiCoO2film with additional annealing at 400 °C had a uniform coating layer between the coating materials and cathode films. This sample showed the best capacity retention of ~91 % with a charge-cut off of 4.5 V after 30 cycles,while the bare cathode film showed a capacity retention of ~32 % under the same conditions. The formation of second phases such as Co-Al-O was observed in the coating films by X-ray photoelectron spectroscopy (XPS). The Co-Al-O containing samples showed a higher initial capacity because of their smaller grain size,but less capacity retention than the Al2O3 containing samples.
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