Investigation of LiCoO2 thin film battery properties with changing Ar/O2 gas atmosphere

Abstract

Thin film batteries are considered the most promising next-generation batteries due to their superior safety and highly developed energy density. The deposition of LiCoO2 thin films with 200 nm thickness was carried out by radio frequency magnetron sputtering. The LiCoO2 thin films were deposited in Ar/O2 gas mixture and coated samples which were deposited in 3% and 10% oxygen amounts, labeled as LCO-3 and LCO-10, respectively. Deposited LCO-3 and LCO-10 thin films possess phase purity and high crystallinity and have a uniform nanostructure with an average grain size of 30-60 nm with homogeneous dispersion. The cyclic voltammetry curves of LCO-3 and LCO-10 electrodes upon electrochemical cycling revealed phase transformations of both materials. The ionic conductivity of the LCO-10 thin films have been exhibited more convenient results than LCO-3 samples. The electrode manifests superior specific capacity of 48 ?Ah/cm2 in the initial cycle. This study provides an information on how LiCoO2 crystal structure and electrochemical properties are affected by changing deposition parameters such at the Ar/O2 gas mixture.