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.