All-Solid-State Rechargeable Lithium Batteries Using LiTi2(PS4)3Cathode with Li2S-P2S5Solid Electrolyte

The electrochemical performances of LiTi2(PS4)3 (LTPS) with a 75Li2S-25P2S5 glass-ceramic solid electrolyte (SE) are investigated. In spite of irreversibility of structural changes, LTPS exhibits a high first discharge capacity of 455 mAh g−1 with good cycling retention of 76% at the 25th cycle between 1.5–3.5 V at 50 mA g−1 at 30°C. In sharp contrast, LTPS with a liquid electrolyte (LE) in a conventional cell loses half of its initial capacity after only 14 cycles. The much poorer performance of LTPS in the LE compared to that in the SE is believed to be associated with dissolution of LTPS into the LE. The results highlight the prospects of exploring electrode materials that are compatible with SEs for all-solid-state batteries.