Preparation and performance of novel LLTO thin film electrolytes for thin film lithium batteries

We prepared a series of lithium lanthanum titanate (LLTO) thin film electrolytes by radio frequency (RF) magnetron sputtering using LLTO targets in a N-2 atmosphere. We also deposited the LLTO thin films in an Ar atmosphere under a same condition as references for comparison. The microstructure morphology and the composition of the thin films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. Results show that the thin film has an amorphous structure with a uniform surface and it is free of pinholes and cracks. Impedance measurements reveal that the ionic conductivity of the electrolytes is beneficial for all solid lithium batteries dependent on the lithium content at room temperature. We found that the amorphous LLTO thin film performs well and it has potential application in microbatteries for use in microelectronic devices.