This thesis focuses growth and characterization of LiCoO₂ thin films using the magnetron sputtering technique for the improvement of its use in lithium-ion batteries. As the rate of energy demand goes up with the need for better performance storage devices, this study aims to enhance deposition parameters for better electrochemical and surface quality of LCO thin films. For the characterization of morphology and composition of the films, Scattering Electron Microscopy (SEM), Energy Dispersive X-ray spectroscopy (EDX), X-ray Diffraction Analysis (XRD), Raman spectroscopy, X-ray Photoelectron Spectroscopy (XPS) and Electrochemical Cyclovoltammetry are used. This research covers the problem related to the interfacial area in between the electrolyte and cathode in all-solid-state lithium-ion batteries (ASSLIBs) and work in the direction that would help to stabilize the interfacial layer and to reduce the ionic resistances. Hence, the present research proposes to optimize the sputtering process as well as study the entire interfacial properties that aim to enhance the general performance. The conclusion drawn in this study is useful to the development of batteries, in identifying the factors that affect the stability of energy storage systems. The findings from this research contribute to the advancement of battery technology, offering valuable insights for developing more efficient and stable energy storage solutions. This work not only underscores the importance of material optimization but also provides a pathway for future innovations in battery technology, ensuring better performance, longevity, and safety in various applications.