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

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 V$^{2+}$ state tend to
interact with sulfur species more easily due to the stronger hybridization
between V$^{2+}$ 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.