Synthesis of Oxide-Based Solid Electrolyte for Lithium Batteries /

Abstract

All-solid-state lithium batteries (ASSLBs) with high energy density, long cycle life, and wide voltage window have become a viable alternative to cope with safety issues of traditional lithium- ion batteries. The use of solid electrolyte eliminates numerous problems associated with liquid electrolytes, such as flammability, leaking and dendrites formation. Sodium super ionic conductors NASICON solid electrolytes are stable towards air and moisture and offer good mechanical and thermal stability. Among NASICON-type solid electrolytes lithium aluminum titanium phosphates (LATP) should have high ionic conductivity at room temperature, low interface impedance between electrode/electrolyte interface, and good compatibility with lithium metal to achieve high performance in ASSLBs.

In this work NASICON-type co-doped L𝑖 1.3+x.y𝐴𝑙0.3-x𝑌x 𝑇𝑖1.7𝑆𝑖y𝑃3-y𝑂12. (LAYTSP) (where x=0.01-0.1 and y=0.1-0.4) solid electrolyte is synthesized via conventional solid-state method at different sintering temperatures, and their intrinsic physical, chemical, and electrochemical properties are investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infra-red spectroscopy (FTIR), and Xray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS). The LAYTSP powders have a homogeneous hexagonal shape and outstanding crystallinity, with the LAYTSP at 900 °C solid electrolyte having a high ionic conductivity of 1.81×10-5 S/cm. These findings show that this novel material is expected to be widely used in ASSLBs in the future.