High-Conductivity\nArgyrodite Li<sub>6</sub>PS<sub>5</sub>Cl Solid Electrolytes Prepared\nvia Optimized Sintering Processes\nfor All-Solid-State Lithium–Sulfur Batteries

Highly Li-ion conductive\nLi₆PS₅Cl solid-state\nelectrolytes (SSEs) were prepared by solid-state sintering method.\nThe influence of sintering temperature and duration on the phase,\nionic conductivity, and activation energy of Li₆PS₅Cl was systematically investigated. The Li₆PS₅Cl electrolyte with a high ionic conductivity of 3.15 ×\n10^–3 S cm^–1 at room temperature\n(RT) was obtained by sintering at 550 °C for just 10 min, which\nwas more efficient taking into account such a short preparation time\nin comparison with other reported methods to synthesize Li₆PS₅Cl SSEs. All-solid-state lithium sulfur batteries (ASSLSBs)\nbased on the Li₆PS₅Cl SSE were assembled by\nusing the nano-sulfur/multiwall carbon nanotube composite combined\nwith Li₆PS₅Cl as the cathode and Li–In\nalloy as the anode. The cell delivered a high discharge capacity of\n1850 mAh g^–1 at RT for the first full cycle at 0.176\nmA cm^–2 (∼0.1C). The discharge capacity was\n1393 mAh g^–1 after 50 cycles. In addition, the Coulombic\nefficiency remained nearly 100% during galvanostatic cycling. The\nexperimental data showed that Li₆PS₅Cl was a\ngood candidate for the SSE used in ASSLSBs.