Sodium-ion battery (SIB) as one of the most promising large-scale energy storage devices has drawn great attention in recent years. However, the development of SIBs is limited by the lacking of proper anodes with long cycling lifespans and large reversible capacities. Here we present rational synthesis of Rayleigh-instability-induced bismuth nanorods encapsulated in N-doped carbon nanotubes (Bi@N-C) using Bi2S3 nanobelts as the template for high-performance SIB. The Bi@N-C electrode delivers superior sodium storage performance in half cells, including a high specific capacity (410 mA h g-1 at 50 mA g-1), long cycling lifespan (1000 cycles), and superior rate capability (368 mA h g-1 at 2 A g-1). When coupled with homemade Na3V2(PO4)3/C in full cells, this electrode also exhibits excellent performances with high power density of 1190 W kg-1 and energy density of 119 Wh kg-1total. The exceptional performance of Bi@N-C is ascribed to the unique nanorod@nanotube structure, which can accommodate volume expansion of Bi during cycling and stabilize the solid electrolyte interphase layer and improve the electronic conductivity.
Keywords: Rayleigh instability; bismuth anode; nanotube; sodium-ion batteries.