Hierarchical flower-like cobalt phosphosulfide derived from Prussian blue analogue as an efficient polysulfides adsorbent for long-life lithium-sulfur batteries

Lithium-sulfur (Li-S) battery as one of the most attractive candidates for energy storage systems has attracted extensive interests. Herein, for the first time, hierarchical flower-like cobalt phosphosulfide architectures (defined as CoSP) derived from Prussian blue analogue (PBA) was fabricated through the conversion of Co-based PBA in PxSy atmosphere. The as-prepared polar CoSP could effectively trap polysulfides through the formation of strong chemical bonds. In addition, after the combination of CoSP with high conductive rGO, the obtained CoSP/rGO as sulfur host material exhibits ultralow capacity decay rate of 0.046% per cycle over 900 cycles at a current density of 1 C. The excellent performance could be attributed to the shortened lithium diffusion pathways, fastened electron transport ability during polysulfide conversion, and increased much more anchor active sites to polysulfides, which is expected to be a promising material for Li-S batteries. It is believed that the as-prepared CoSP/rGO architectures will shed light on the development of novel promising materials for Li-S batteries with high cycle stability.