Mesoporous Sn4P3-graphene aerogel composite as a high-performance anode in sodium ion batteries

Abstract Sodium ion batteries (SIBs) are deemed as the potential alternative for lithium ion batteries (LIBs) in the application of large-scale energy storage and conversion. The favorable anode materials play an important role for high-performance SIBs. Sn4P3 has been considered as one of the promising anode materials for sodium ion batteries due to the combination of high electrical conductivity from Sn and high specific capacity from P. In this work, Sn4P3/graphene aerogel (Sn4P3-GA) composite is prepared via a rapid low-temperature phosphidation reaction from SnO2-GA composite. The structural and morphological characterizations demonstrate that the Sn4P3 nanoparticles with an average size of 8 nm are uniformly and tightly embedded on the surface of 3D GA. The unique 3D network structure as well as the synergistic effect between graphene nanosheets and Sn4P3 nanoparticles would endow the as-prepared Sn4P3-GA composite with good electrochemical sodium storage performance. It delivers the high initial discharge capacity of 1180 mAh g−1 at 0.1 A g−1 and good cycle stability (657 mAh g−1 at 0.1 A g−1 after 100 cycles). Meanwhile, the Sn4P3-GA composite exhibits high-rate capacity of 462 and 403 mAh g−1 at a current density of 1 and 2 A g−1, respectively. Moreover, the contribution of the pseudocapacitance capacity can explicate the origin of good rate capability of the Sn4P3-GA composite. This work demonstrates the great potential of Sn4P3-GA composite as an alternative anode material for the low-cost and high-performance sodium ion batteries.