Novel K₃V₂(PO₄)₃/C Bundled Nanowires as Superior Sodium‐Ion Battery Electrode with Ultrahigh Cycling Stability

Abstract

Sodium‐ion battery has captured much attention due to the abundant sodium resources and potentially low cost. However, it suffers from poor cycling stability and low diffusion coefficient, which seriously limit its widespread application. Here, K 3 V 2 (PO 4 ) 3 /C bundled nanowires are fabricated usinga facile organic acid‐assisted method. With a highly stable framework, nanoporous structure, and conductive carbon coating, the K 3 V 2 (PO 4 ) 3 /C bundled nanowires manifest excellent electrochemical performances in sodium‐ion battery. A stable capacity of 119 mAh g −1 can be achieved at 100 mA g −1 . Even at a high current density of 2000 mA g −1 , 96.0% of the capacity can be retained after 2000 charge–discharge cycles. Comparing with K 3 V 2 (PO 4 ) 3 /C blocks, the K 3 V 2 (PO 4 ) 3 /C bundled nanowires show significantly improved cycling stability. This work provides a facile and effective approach to enhance the electrochemical performance of sodium‐ion batteries.