Characterization of Li2S–P2S5 glass-ceramics as a solid electrolyte for lithium secondary batteries

Glass-ceramic solid electrolytes were prepared by crystallization of the mechanically milled 80Li2S·20P2S5 glass and their electrical and electrochemical properties were examined. The glass-ceramics exhibited favorable features as a solid electrolyte for lithium secondary batteries such as high ambient temperature conductivity of 7.2×10−4 S cm−1, unity of lithium transport number, wide electrochemical window, and high stability against lithium metal. All-solid-state cells In/80Li2S·20P2S5 glass-ceramic/LiCoO2 worked as lithium secondary batteries at room temperature and maintained large discharge capacity of about 100 mA h g−1 up to the 200th cycle with the charge–discharge efficiency of 100%.