SOLID ELECTROLYTES FOR LITHIUM BATTERIES

The use of solid electrolytes to produce an all-solid-state lithium battery is regarded as one promising alterative for improved safety. In this work, the researchers synthesized cubic garnettype ceramic electrolyte Li6.75La3Zr1.75Ta0.25O12 (LLZTO) via the coprecipitation method. For the characterization, the phase content was determined using X-ray diffraction (XRD), morphology was obtained by using a scanning electron microscope (SEM), and conductivity was measured by AC impedance spectroscopy using a frequency response analyzer. The results showed that the room temperature total conductivity and activation energies of LLZTO were 7.2x10(-6) S/cm and 0.31-0.46 eV, respectively. Composite electrolytes were prepared by mixing LLZTO with a ceramic (Li1.4Al0.4Ti1.6(PO4)) (NASICON) or a polymer polyethylene oxide (PEO) with LiClO4 salt. The LLZTO-NASICON composite showed a higher total conductivity of 1.2x10(-5) S/cm and activation energies of 0.23-0.58 eV. Compared to LLZTO, the LLZTO-PEO(LiClO4) composite showed a similar room temperature total conductivity of 1.2x10(-6) S/cm, but a higher activation energy of 0.59-0.85 eV.