Room-temperature synthesis of crystallized LiCoO2 thin films by electrochemical technique

LiCoO2 thin films have been directly synthesized on cobalt substrate in LiOH solution at room temperature by electrochemical method. The obtained LiCoO2 thin films were characterized by X-ray diffraction (XRD), scanning electronic microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The influence of electrochemical reaction time, current density and concentration of LiOH solution on the crystal structure and morphology of the obtained LiCoO2 thin films was discussed emphatically. Our results show that the as-synthesized LiCoO2 films all are pure hexagonal structure. The crystallinity, densification and uniformity of the films increase with increasing electrochemical reaction time, current density as well as concentration of LiOH solution and then decrease. The preferable electrochemical reaction conditions were optimized as: electrochemical reaction time is 50 h, current density is 1 mA cm−2 and concentration of LiOH solution is 3 mol dm−3.

Research highlightsThis manuscript reports our original research work on the synthesis and characterization of LiCoO2 films by room temperature electrochemical technique. Compared to previous reports on similar work, the present work is devoted to the preparation of LiCoO2 films via electrochemical technique at room temperature, which has great advantages in experimental equipment and energy consumption, in other words, it is a very convenient and mild deposition route for LiCoO2 films. Moreover, the influences of electrochemical reaction time, current density and concentration of LiOH solution on the morphology and crystal structure have been discussed emphatically, and the morphology and microstructures of the obtained LiCoO2 films have been markedly improved.