Highly Stable Sb/C Anode for K⁺ and Na⁺ Energy Storage Enabled by Pulsed Laser Ablation and Polydopamine Coating

Abstract Potassium‐ and sodium‐ion batteries (PIBs and SIBs) have great potential as the next‐generation energy application owing to the natural abundance of K and Na. Antimony (Sb) is a suitable alloying‐type anode for PIBs and SIBs due to its high theoretical capacity and proper operation voltage; yet, the severe volume variation remains a challenge. Herein, a preparation of N‐doped carbon‐wrapped Sb nanoparticles (L‐Sb/NC) using pulsed laser ablation and polydopamine coating techniques, is reported. As the anode for PIB and SIB, the L‐Sb/NC delivers superior rate capabilities and excellent cycle stabilities (442.2 and 390.5 mA h g⁻¹ after 250 cycles with the capacity decay of 0.037% and 0.038% per cycle) at the current densities of 0.5 and 1.0 A g⁻¹, respectively. Operando X‐ray diffraction reveals the facilitated and stable potassiation and sodiation mechanisms of L‐Sb/NC enabled by its optimal core–shell structure. Furthermore, the SIB full cell fabricated with L‐Sb/NC and Na₃V₂(PO₄)₂F₃ shows outstanding electrochemical performances, demonstrating its practical energy storage application.