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.
Chen et al. (Sat,) studied this question.