(30b) Uniformly Embedded Cobalt Phosphide Nanoparticles in Carbon Nanofibers As Sulfur Host Via Co-PBA in-Situ Growth for High-Performance Li-S Batteries

Due to their high theoretical capacity and energy density, Li-S batteries have emerged as promising candidates for the next generation of commercial energy devices, attracting significant attention. However, existing challenges such as the shuttle effect of polysulfides and the inert conductivity of sulfur have hindered the development of these batteries. To overcome these challenges, researchers have recently explored the use of hierarchical carbon hybrid materials incorporating metallic compounds to improve the electrochemical performance of the cell. One such material, the use of prussian blue analogues (PBA) combined with carbon nanofibers as cathode materials has been reported rarely. In this study, a CoP/CNFs (cobalt phosphate/carbon nanofibers) composite was obtained by pyrolyzing electrospun fibers from PAN with in-situ grown Co-PBA, followed by phosphorization. The resulting CoP nanoparticles can efficiently promote the catalytic conversion of lithium polysulfide (LiPSs) due to a reduced energy barrier, effectively inhibiting shuttle-effect. The interconnected CNFs structure provides a high conductive framework and large exposed area, which accelerates electron transport and Li ions movement due to a reduction in accessing distance, and improvement in the absorption ability of LiPSs. The synergistic effect of the CoP nanoparticles and CNFs structure contributes to the high performance of Li-S cells, including cycling and rate capability. This promising strategy expands the routes for preparing cathode materials with high performance in Li-S batteries, overcoming existing challenges and improving the electrochemical performance of the cell.