Integrating anti-aggregation Ta-Se motifs into copper selenide for fast and robust sodium-ion storage.

We report a novel bimetallic selenide Cu 3 TaSe 4 anode for sodium-ion batteries synthesized via a one-step solid-state method. The integration of Ta-Se motifs into copper selenide forms a cubic grid structure that prevents copper atom aggregation and mitigates electrode failure. Cu 3 TaSe 4 exhibits a high specific capacity of 305 mAh g -1 at 1 C, excellent rate performance of 286 mAh g -1 at 50 C, and superior cycling stability with 272 mAh g -1 after 3500 cycles at 20 C. This work demonstrates the potential of bimetallic selenides in enhancing sodium-ion battery performance.