Bimetallic alloy SbSn nanodots filled in electrospun N-doped carbon fibers for high performance Na-ion battery anode

Abstract

In the current state of research, it is still a challenge to develop high-performance electrode materials with high energy density and long cycle life for sodium-ion batteries. For example, Owing to the serious volume changes of the anode active materials in the actual application of the sodium-ion batteries, which resulting in irreversible capacity loss and poor cycle stability of the battery. Taking advantage of different redox potentials of metals has proven to be an effective method to reduce volume changes. Here SbSn nanodots are encapsulated in nitrogen-doped carbon nanofibers prepared by electrospinning. The different oxidation depotentialities of Sn and Sb in SbSn helps to reduce the volume expansion during the cycle, three-dimensional interconnected N-doped carbon nanofibers(NCNFs) have a high specific surface area and high porosity, which are conducive to the transmission of electrons and ions.The resulting SbSn nanodots filled in N-doped carbon nanofibers(SbSn@NCNFs) composite exhibits impressive electrochemical performance, with high discharge capacity (808mAh g−1at 100mAg−1), rate capability(331mAh g−1 at 1.6Ag−1) and excellent cycle stability (331mAh g−1 at 100mAg−1 after 500 cycles). By using this material as the anode and the Na3V2(PO4)2F3 nano-flower anchored on three-dimensional carbon sheets (NVPF@3Dc) material manufactured by our research group as the cathode, a full Sodium-ion battery(SIB) with commercial value is assembled.