Lithium cobalt oxide crystallization on flexible polyimide substrate

This work reports the fabrication and characterization of lithium cobalt oxide films (LiCoO2) on flexible Kapton® substrate. LiCoO2 is commonly used as cathode of lithium microbatteries but needs an annealing of 700 °C, which is not compatible with most flexible substrates. LiCoO2 films were deposited by reactive RF sputtering followed by an annealing process at 400 °C for 1 h in vacuum and air atmospheres both in silicon and Kapton® substrates. Raman spectroscopy, X-ray diffraction patterns and scanning electron microscopy images were used to evaluate samples crystallinity and morphology. Films fabricated in Kapton® and silicon substrates were compared.This work was financial supported by FEDER/COMPETE and FCT funds with the Project PTDC/EEA-ELC/114713/2009, strategic Project PEst-C/FIS/UI607/2013, PEst-C/QUI/UI0686/2013 and UID/EEA/04436/2013, first author scholarship SFRH/BD/78217/2011 and third author scholarship SFRH/BPD/95905/2013