Bifunctional NiCoP nanofiber arrayed on carbon cloth for fast polysulfide conversion and uniform lithium deposition...

The severe polysulfides shuttling and irregular lithium dendrites impede the widespread adoption of lithium-sulfur (Li-S) batteries. Here, a sulfiphilic/lithiophilic NiCoP nanofiber arrayed on carbon cloth (NiCoP@CC) as the sulfur/lithium host is reported, providing a dual solution for both cathode and anode issues. Both theoretical calculations and experiments confirm that NiCoP@CC enhances the cycling stability of sulfur cathode and lithium anode by facilitating polysulfides conversion and homogenizing lithium deposition. Additionally, the unique structure of NiCoP nanofiber-decorated carbon cloth provides ample space to accommodate active materials and ensures even distribution of sulfur and lithium. Consequently, Li-S half cells containing NiCoP@CC exhibit an outstanding cycling life of 900 cycles at 1 C. Moreover, the Li@NiCoP@CC electrode achieves a stable, long cycling performance for 3000 h at 1 mA cm^-2. Notably, Li-S full cells show enhanced cycling performance, maintaining stability over 750 cycles with a decay rate of 0.04 % per cycle at 1 C and a low N/P (negative/positive capacity) ratio of 2.4. A high areal capacity of 7.75mAh cm^-2 is obtained at a high sulfur loading of 8.6 mg cm^-2. This study presents a new strategy for designing bimetallic phosphides as bifunctional materials to overcome difficulties in practical Li-S batteries.