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.