Transformation of P2S5 into a Solid Electrolyte with Ionic Conductivity at the Positive Composite Electrode of All-Solid-State Lithium-Sulfur Batteries

Battery performance of an all-solid-state lithium-sulfur (Li-S) cell with a P2S5-based positive composite electrode was investigated in the absence of solid electrolyte at the positive composite electrode. In the positive composite electrode, P2S5 without ionic conductivity was transformed into a solid electrolyte with ionic conductivity by incorporating lithium ions into P2S5 during the first charge-discharge cycle. Therefore, the all-solid-state Li-S cell with P2S5-based positive composite electrode behaved as a secondary battery. This positive composite electrode is very low cost because it did not use an expensive solid electrolyte. In addition to using a cost-effective positive composite electrode with a sulfur content of 60 wt%, the all-solid-state Li-S cell exhibited an extremely high capacity of 1042 mAhg(-1) under 6.4 mAcm(-2) at 25 degrees C.