Abstract: | Sodium‐ion batteries (SIBs) based on flexible electrode materials are being investigated recently for improving sluggish kinetics and developing energy density. Transition metal selenides present excellent conductivity and high capacity; nevertheless, their low conductivity and serious volume expansion raise challenging issues of inferior lifespan and capacity fading. Herein, an in‐situ construction method through carbonization and selenide synergistic effect is skillfully designed to synthesize a flexible electrode of bone‐like CoSe2 nano‐thorn coated on porous carbon cloth. The designed flexible CoSe2 electrode with stable structural feature displays enhanced Na‐ion storage capabilities with good rate performance and outstanding cycling stability. As expected, the designed SIBs with flexible BL?CoSe2/PCC electrode display excellent reversible capacity with 360.7 mAh g?1 after 180 cycles at a current density of 0.1 A g?1. |