Journal of Materials Science, Vol.56, No.18, 11000-11010, 2021
One-step large-scale fabrication of Bi@N-doped carbon for ultrahigh-rate and long-life sodium-ion battery anodes
Bismuth has been deemed to be the promising anode material for sodium-ion batteries on account of large volumetric capacity (3800 mAh cm(-3)) and high electrical conductivity. However, huge volume change during sodiation/desodiation usually causes pulverization of electrode, leading to poor rate performance and cycling stability. Herein, one-step large-scale fabrication of bismuth@N-doped carbon (Bi@C) is proposed to construct well-behaved electrode materials for sodium-ion batteries. Surprisingly, the Bi@C anode presents superior sodium storage performance, manifesting a high specific capacity (346 mAh g(-1) at 0.1 A g(-1)), excellent rate stability (274 mAh g(-1) under ultrahigh current density of 50 A g(-1)) and long life span (344 mAh g(-1) at 1 A g(-1) after cycling over 1500 times, 0.003% loss per cycle). Such excellent performances of Bi@C are attributed to the nano-sized Bi particles (similar to 15 nm) encapsulated by thin carbon layer doped with N. These structural characteristics optimize the ion transfer and increase the accessible area between electrode and electrolyte, and then give a high capacitive contribution to the capacity.