Metal-phosphide-doped Li7P3S11 glass-ceramic electrolyte with high ionic conductivity for all-solid-state lithium-sulfur batteries

Novel glass-ceramic electrolytes of (100-x) (70Li(2)S-30P(2)S(5))-xNi(2)P (x = 0, 1, 2, 3, 4) with high ionic conductivity were proposed with the addition of Ni2P. The 2 mol% Ni2P containing electrolyte (Li7Ni0.2P3.1S11) displays the highest lithium-ion conductivity of 2.22 mS cm(-1) at room temperature, which is 1.6 times higher than pristine Li7P3S11. By direct combination with Li2S, the fabricated Li7Ni0.2P3.1S11-Li2S all-solid-state battery exhibits an initial discharge capacity of 429 mAh g(-1) at 0.064 mA cm(-2) and 454 mAh g(-1) at 20th charging/discharging cycle with a high Coulombic efficiency of 99.7%.