Multiscale Kinetics‐Enhanced and Interphase‐Stabilized Hierarchical Architecture Design Enables Fast‐Charging and Longevous Sodium‐Ion Batteries

ABSTRACT Achieving ultrafast chargeability and long‐term durability in sodium (Na) ion battery (SIB) anodes is highly sought after, but intrinsically limited by their sluggish Na + transport kinetics and aggressive interfacial degradation. Here, we proposed a rationally designed bismuth‐confined micro‐rod@nitrogen‐doped carbon (Bi‐MR@NC) composite to address these limitations. The engineered structure achieves full encapsulation of ultrahigh nano‐Bi content (90 nm, 91 wt.%) in a sheet‐assembled carbon microrod (8–12 µm) architecture, enabling dense electrode construction while maintaining rapid ion/electron transport kinetics, and robust interfacial stability during long‐term cycling, as ascertained by detailed material characterizations and electrochemical evidences. Therefore, Bi‐MR@NC anode delivers exceptional long‐term cyclability of 82.4% capacity retention over 25 000 cycles at 10 A g −1 , ultrafast charging capability (220 A g −1 , charge/discharge completed in 9.2 s), and practically relevant areal capacity of 2.4 mAh cm −2 after 1000 cycles at 8.97 mA cm −2 . Remarkably, full cells with a practical high‐mass‐loading Na 3 V 2 (PO 4 ) 3 (NVP) cathode (19.48 mg cm −2 ) sustain 1.56 mAh cm −2 with 86.9% capacity retention after 1000 cycles at 3.9 mA cm −2 . Pouch cell tested under 10 C fast‐charging condition demonstrates long‐lasting cyclability over 3000 cycles with only 0.01% capacity fading per cycle. This work establishes a generalizable architectural strategy for fast‐charging and long‐life alloy anodes in next‐generation batteries.