Excellent electrochemical properties, Li ion dynamics and room temperature work function of Li₂MnO₃cathode thin films

We report on excellent electrochemical properties, Li ion diffusion coefficient and work function of Li₂MnO₃thin films fabricated by RF sputtering technique. The x-ray diffraction study confirms the formation of Li₂MnO₃thin film in layered structure. The x-ray photoelectron spectroscopy study confirms the existence of Li and Mn ions and their appropriate oxidation states in Li₂MnO₃thin film. Work function of the Li₂MnO₃thin film has been measured using scanning Kelvin probe microscopy and is found to be 5.51 eV. Electrochemical studies show that the Li₂MnO₃thin film exhibits oxidation and reduction peaks at 2.98 V and 2.81 V respectively with the discharging capacity of 10μAh cm^-2in the first cycle and 9μAh cm^-2in the 100th cycle at aCrate of 25μA cm^-2. Electrochemical stability of Li₂MnO₃thin film is probed by measuring the charge discharge profile with high sweep rate of 500 mV s^-1. Li ion diffusion coefficient value is seen to 1.6 × 10^-14cm²s^-1and 2.56 × 10^-14cm²s^-1before and after the cycling respectively. Electrochemical studies indicate that Li₂MnO₃thin films can be utilized as a promising cathode layer in all-solid thin film battery fabrication.