Scalable Li-Ion Battery with Metal/Metal Oxide Sulfur Cathode and Lithiated Silicon Oxide/Carbon Anode.

Abstract

A Li-ion battery combines a cathode benefitting from Sn and MnO₂ with high sulfur content, and a lithiated anode including fumed silica, few layer graphene (FLG) and amorphous carbon. This battery is considered a scalable version of the system based on lithium-sulfur (Li-S) conversion, since it exploits at the anode the Li-ion electrochemistry instead of Li-metal stripping/deposition. Sn and MnO₂ are used as cathode additives to improve the electrochemical process, increase sulfur utilization, while mitigating the polysulfides loss typical of Li-S devices. The cathode demonstrates in half-cell a maximum capacity of ~1170 mAh g_S ^-1, rate performance extended over 1 C, and retention of 250 cycles. The anode undergoes Li-(de)alloying with silicon, Li-(de)insertion into amorphous carbon, and Li-(de)intercalation through FLG, with capacity of 500 mAh g^-1 in half-cell, completely retained over 400 cycles. The full-cells are assembled by combining a sulfur cathode with active material loading up to 3 mg cm^-2 and lithiated version of the anode, achieved either using an electrochemical pathway or a chemical one. The cells deliver at C/5 initial capacity higher than 1000 mAh g_S ^-1, retained for over ~40 % upon 400 cycles. The battery is considered a promising energy storage system for possible scaling-up in pouch or cylindrical cells.