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LiTi y Co 1-y O2 (y = 0, 0.02, 0.05, 0.1) thin films were deposited on metalized Si substrates using RF magnetron sputtering technique. The films were deposited at a substrate temperature of 250 °C with subsequent annealing at 600 °C for 3 h in controlled oxygen environment. The films exhibited predominant (003), (101), and (104) orientations representing single-phase hexagonal structure with R $$ \overline{3} $$ m space group. Two well-defined Raman peaks observed at 489 and 598 cm−1 corresponding to E g and A1g modes confirm the hexagonal layered structure. The grain size and grain distribution were observed using atomic force microscopy. The cyclic voltammetry studies on Pt//LiTi y Co1-y O2 film cathodes in aqueous region exhibited perfect redox peaks at expected potentials. The Pt//LiTi0.02Co0.98O2 film cathode exhibited better discharge capacity of about 65 μA h cm−2 μm−1 with good cycling stability compared to pure Pt//LiCoO2. The electrochemical impedance analysis revealed a lower charge transfer resistance in Ti doped LiCoO2 film cathode, resulting better discharge capacity.

The microstructural and electrochemical properties of rf-sputtered LiMn2O4 films were investigated as a function of post-deposition process. The degree of crystallization in the films gradually increased with the increase of annealing temperature (T a). The films annealed at T a = 973 K exhibited characteristic peaks with predominant (111) orientation representing the cubic spinel structure of Fd3m symmetry. The estimated Mn–Mn and Mn–O distances obtained from the X-ray diffraction data were observed to be increased slightly with T a. Characteristic changes in surface morphological features were observed as a function of T a as evidenced from scanning electron microscopy. The estimated root mean square (RMS) roughness of the films increased from 97 to 161 nm with augmentation of T a. The electrochemical studies, viz. cyclic voltammetry (CV), specific discharge capacity and Li ion diffusion coefficient were carried out for annealed LiMn2O4 films in saturated aqueous electrolyte (Li2SO4) in the potential window of 0–1.2 V and correlated with surface morphology and grain size. The LiMn2O4 films annealed at T a = 973 K exhibited better electrochemical performance and demonstrated a discharge capacity of about 53.5 μA h cm−2 μm−1 with diffusion coefficient of 1.2 × 10−13 cm2 s−1.