Highly-ordered arrangement of Co(OH)F filaments: Planting flower-like Co(OH)F in conductive membrane substrate accelerating Li⁺ transfer and redox reaction in Li-S batteries

Here, the conventionally disordered Co(OH)F filaments are rearranged to form highly-ordered flower-like Co(OH)F architectures in a conductive membrane substrate. The important findings contribute to designing delicate nanostructures and improving the catalytic activity of advanced materials for energy applications. The hierarchically porous CNT@NC membrane with CNT as the core and N-doped carbon as the crosslinking shell is scalably designed firstly for strengthening the transport of Li+ and electrons in the electrode, providing an ultrahigh porosity for growing flower-like Co(OH)F on both surfaces and interior of the membrane, as well as offering electrons for the redox reactions through the roots of the Co(OH)F flowers. Furthermore, the ordered Co (OH)F bundles with divergent and open-ended structures provide the catalyst with the broad reaction interface and active sites for polysulfides (LiPSs) anchoring and catalytic conversion at a low energy barrier, significantly facilitating the diffusion of ions and electrolyte in the catalyst, and thus effectively alleviating the shuttle effect. Owing to the synergistic effect between the conductive membrane substrate and the grown Co(OH)F catalyst, the Co(OH)F-CNT@NC cathode generates a high reversible capacity and excellent long-term cycling performance (622 mAh.g(-1) at 1C after 600 cycles). Conclusively, the proposed facile strategy provides insights regarding the design of novel cathode materials for high-areal-capacity Li-S batteries.