Efficiently immobilizing and converting polysulfide by a phosphorus doped carbon microtube textile interlayer for high-performance lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries are regarded as the potential substitution for the lithium-ion batteries owing to the ultrahigh theoretical energy density and specific capacity. Nevertheless, the low sulfur utilization and the severe “shuttle effect” impede the commercialization of them. Herein, a phosphorus doped carbonized cotton cloth (PCCC) interlayer is proposed to handle these problems. The PCCC interlayer can not only act as an upper current collector and a physical lithium polysulfides (LIPS) barrier due to its high conductivity and knitted structure, but also chemically adsorb the LIPS and catalyze their conversion owing to the heteroatom doping of phosphorus. The synergistic effects of immobilizing and converting the LIPS lead to greatly reduced “shuttle effect” and high sulfur utilization. As a consequence, the Li-S batteries with the PCCC interlayer demonstrate decent cycling performance as well as ultrahigh rate capability by releasing a high initial discharge capacity of 1138 mA h g−1 at 0.5 C with a small capacity fading rate of 0.054% per cycle, and achieving an astonishing discharge capacity up to 642 mA h g−1 at 10 C.