Bifunctional NiCoP nanofiber arrayed on carbon cloth for fast polysulfide conversion and uniform lithium deposition in lithium sulfur batteries

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.