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

Abstract

We report a novel bimetallic selenide Cu₃TaSe₄ 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. Cu₃TaSe₄ 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.