关键词: 低成本, 球磨法, 硫化物固态电解质, 锂离子电导率

Abstract:

With the shortage of energy and environmental pollution, the storage of electric energy is getting more attention all over the world. In order to improve the energy density and safety performance of batteries, uses of solid electrolyte become more and more popular. However, because the conductivity of solid electrolyte is not comparable to that of liquid electrolyte, the solid electrolyte application has certain limitations. With the efforts of researchers from various countries, there are several different solid electrolytes having better conductivity, for instance, sulfide solid electrolyte and oxide solid electrolyte. Sulfide solid electrolyte is a highly promising solid electrolyte material because of its high room temperature conductivity, good thermal stability and wide electrochemical window. It has outstanding advantages in high power and normal temperature solid state batteries. However, the application of expensive Li₂S raw materials required high-purity has been hampered. In this paper, Li_6-xPS_5-xCl_x (x = 0.5) solid electrolyte was prepared by ball milling using low-cost raw materials such as elemental lithium metal (99.9%), sublimed sulfur (CP), P₂S₅ (AR) and LiCl (AR). The as-prepared Li_6-xPS_5-xCl_x solid electrolyte powder was characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), and the cold-pressed Li_6-xPS_5-xCl_x tablets were tested for cycle performance and electrical conductivity in Li_6-xPS_5-xCl_x/Li half-cell. The results showed that through the pressure-free sintering at 550 ^oC, the total lithium-ion conductivity of the solid electrolyte at room temperature was 8.29×10 ^-4 S·cm ^-1, making commercialization of solid-state batteries possible.

Key words: low cost, ball milling, sulfide solid electrolyte, lithium ion conductivity