Self-standing and high-performance B4C/Sn/acetylene black@reduced graphene oxide films as sodium-ion half/full battery anodes

Sn-based materials show great potentials as sodium-ion battery (SIB) anodes. However, limited to the preparation process and expensive raw materials, it is a great challenge to large-scale produce self-standing Sn-based materials. Herein, we develop a cost-effective and large-scale production method to fabricate flexible B4C/Sn/acetylene black@reduced graphene oxide (B4C/Sn/AB@rGO) films as self-standing SIB anodes by using high energy ball milling technology and self-standing process. In the film, the coated B4C acts as a conductor to enhance the internal conductivity and AB is used as a shell of B4C/Sn to accelerate the absorption of electrolyte solution, while rGO plays a role as a tie to connect B4C/Sn/AB units to accelerate the electronic transmission and simultaneously alleviate the volume expansion during the charge/discharge process. Finally, the B4C/Sn/AB@rGO films as the SIB anodes deliver a high reversible capacity of 393.4 mA h g−1 at 0.1 A g−1 and excellent cycling stability at 1 A g−1 with the reversible capacity of 155.5 mA h g−1 over 500 cycles. Moreover, the assembled sodium-ion full cell shows a stable capacity at 201.5 mA h g−1 for 50 cycles at 0.1 A g−1. This study indicates that our synthetic B4C/Sn/AB@rGO film has a great potential as the self-standing SIB anode