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

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, K3V2(PO4)3/C bundled nanowires are fabricated usinga facile organic acid‐assisted method. With a highly stable framework, nanoporous structure, and conductive carbon coating, the K3V2(PO4)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 K3V2(PO4)3/C blocks, the K3V2(PO4)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. K3V2(PO4)3/C bundled nanowires are designed and fabricated using a facile organic acid‐assisted method. Ex situ and in situ X‐ray diffraction (XRD) results indicate that the stable framework of the K3V2(PO4)3/C bundled nanowires is responsible for the excellent cycling stability. Constructing K3V2(PO4)3/C bundled nanowires provides an effective approach to enhance the electrochemical performance for sodium‐ion batteries.