Hierarchical Flower‐Like Cu ₃ BiS ₃ @ppy as High‐Performance Anode for Sodium‐Ion Storage

Abstract Bimetallic sulfides (BMSs) with exceptional conductivity and abundant redox active sites are the potential anode materials for sodium‐ion batteries (SIBs). Herein, the polypyrrole‐coated hierarchical flower‐like Cu 3 BiS 3 composite (Cu 3 BiS 3 @ppy) had been synthesized with the use of hydrothermal method and organic polymerization process. The synergistic effects of hierarchical BMSs and conductive carbon layer provide convenient diffusion channels for Na + , abundant Na + reaction active sites, and buffering the volumetric variation which reflect in the impressive electrochemical performance with high reversible capacity of 327 mA h g −1 after 1000 cycles at 5 A g −1 . Furthermore, the Cu 3 BiS 3 @ppy exhibited excellent rate capacity of 331 mA h g −1 at 10 A g −1 . Kinetic analysis also clarified that Cu 3 BiS 3 @ppy possesses ultrafast sodiation property, which revealed the potential to be a promising candidate for electrode material of SIBs.