Sn/C composite anodes for bulk-type all-solid-state batteries

A simple method of realizing all-solid-state lithium batteries (ASS-LIBs), employing a Sn/C composite anode and glassy solid electrolyte LiI-Li₃PS₄ (LPSI), possessing desirable capacity and cycle life, is proposed. The composite anode, containing Sn/C, LPSI, and carbon fiber, is synthesized via a straightforward, one-step, manual grinding. Potentiodynamic cycling with galvanostatic acceleration (PCGA) analysis and cyclic voltammetry of Sn/C LPSI Li cells demonstrate that electrochemical processes of graphite are promoted by integrating it with Sn. The improvement appears as increased battery capacity in galvanostatic charge-discharge cycling. The Sn/C LPSI Li exhibits a capacity of 400 mAh g⁻¹ in the 1^st cycle at 0.033C, which is about 83% of the nominal capacity of the composite. Throughout the course of 30 cycles, the cell retains a capacity above 320 mAh g⁻¹ and a coulombic efficiency above 98%. The retention of its high capacity suggests that the pulverization of Sn was physically suppressed by using solid-state materials, i.e. LPSI and graphite. It is demonstrated that the combination of LPSI electrolyte and Sn/C enables a simple and time-efficient preparation of ASS-LIBs with stable and safe performance.