Electron-delocalization catalyzers for high performance, low-temperature Li–S batteries

Abstract

The extremely depressive conversion kinetics of polysulfides due to sluggish Li⁺ diffusion kinetics remain to be resolved for low-temperature Li–S batteries (LT-LSB). Herein, the strategy for electron-delocalization of nanocatalysts has been designed through introducing oxygen defects on vanadium trioxide that was anchored on a porous carbon network (ODVO@PCN). The reconstructed active sites of the V²⁺ state tend to interact with sulfur species more easily due to the stronger hybridization between V²⁺ sites and S sites in sulfur species, allowing enhanced Li⁺ transformation kinetics across the electrolyte/electrode interface for a fast redox reaction in the low-temperature surrounding. Consequently, at a low temperature of 0 °C, the cell with the ODVO@PCN kinetic promotor exhibits 501 mA h g⁻¹ at 1C and a long life time of up to 400 cycles at 0.5C. Reduced to ultralow −10 °C, the cell still provides a capacity of 706 mA h g⁻¹ and stabilizes a remarkable capacity retention of 85% after 100 cycles.