Combustion Synthesized Porous Bismuth/N-Doped Carbon Nanocomposite for Reversible Sodiation in a Sodium-Ion Battery

With a stable operating potential and a high theoretical specific capacity, bismuth metal is a promising candidate as the anode for sodium-ion batteries (SIBs). However, its rate capability, long cycling stability, sluggish kinetics, and electrode structure stability still needs to be significantly improved. Herein, a three-dimensional porous bismuth/nitrogen-doped carbon composite (Bi/N–C) was prepared via a scalable and facile solution combustion synthesis (SCS) method. The open porous structure allows fast Na+ transport and accommodates the 3.5 times volume changes during the charging/discharging process in SIB. The porous Bi/N–C anode exhibits an excellent rate capability of 379 mAh g–1 at 0.05 A g–1 close to the theoretical value of 385 mAh g–1 and a stable reversible capacity at high rate of 206 mAh g–1 at 5.0 A g–1, after 1600 cycles. A high performance full SIB was demonstrated using the porous Bi/N–C anode and a Na3V2(PO4)3 cathode with a specific energy of ∼120 Wh kg–1 at a high specific power of 81 W kg–1 based on the total mass of anode and cathode materials. These remarkable performances of the porous Bi/N–C, together with the simple energy-efficient synthesis, can motivate extension of the solution combustion synthesis to fabricate materials for other electrochemical power devices.