Galvanic Replacement Synthesis of Highly Uniform Sb Nanotubes: Reaction Mechanism and Enhanced Sodium Storage Performance.

One-dimensional nanotubes are very useful for achieving excellent performance in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) due to the fact that tubular structures can effectively alleviate the structural strain and shorten the ion diffusion length during repeated cycling. In this work, we report a Cu2Sb-mediated growth strategy to controllably fabricate highly uniform Sb nanotubes (NTs), as well as Cu@Cu2Sb and Cu2Sb@Sb composite NTs, via a facile galvanic replacement reaction using Cu nanowires (NWs) as sacrificial templates. Benefiting from their structural merits, the Sb NTs manifest excellent sodium storage performance with superior rate performance (286 mAh g-1 at 10 A g-1) and extraordinary cycling stability (342 mAh g-1 after 6000 cycles at 1 A g-1). Furthermore, a full cell with Sb NTs as anode and Na3(VOPO4)2F as cathode exhibits a high energy density (252 Wh kg-1) and high output voltage (2.7 V), revealing their significant application promise in the next-generation SIBs.