Functional Carbon Interlayer with Indium Oxide-Rich Nanoparticles for High-Performance Lithium–Sulfur Batteries

Lithium–sulfur batteries are gaining a lot of attention from researchers due to their high energy density, high theoretical specific capacity, and low raw material prices. Nevertheless, the dissolution and diffusion of certain polysulfides during charge and discharge cycles result in a shuttle effect, while reduced sulfur utilization remains a barrier to their commercial viability. In this study, we propose the use of carbon nanofibers enriched with indium oxide nanoparticles (be called In₂O₃@CNF) as a functional interlayer for lithium–sulfur batteries. The interlayer of this innovation serves a dual purpose. Indium oxide nanoparticles can adsorb polysulfide to inhibit the shuttle effect, and accelerate the catalytic transformation of polysulfide to enhance the reaction kinetics. As a result, the electrochemical performance of the battery with the In₂O₃@CNF interlayer exhibited remarkable improvements. The initial discharge capacity was 1187 mAh g⁻¹ at 0.2 C and the capacity retention was 77.5 % after 100 cycles. Furthermore, even at a higher current density of 1 C, the battery demonstrated a substantial initial capacity of 997 mAh g⁻¹, maintaining a capacity retention of 589 mAh g⁻¹ after 400 cycles. Notably, the battery exhibited stable Coulombic efficiency (CE) and minimal single-cycle capacity decay (0.1 %).