A mesoporous antimony-based nanocomposite for advanced sodium ion batteries

Developing advanced electrode materials and understanding the electrochemistry of electrode reactions are two main issues to be addressed for high-performance sodium ion batteries (SIBs). Through a one-step dealloying strategy which simultaneously incorporates the nanoarchitecture, mesoporous structure and nanocomposite of electrode materials, here we synthesized novel Sb2O3@Sb nanocomposite with an ultrafine bicontinuous mesoporous structure. When being used as an anode for SIBs, the Sb2O3@Sb nanocomposite exhibits ultrahigh specific capacity (659 mA h g(-1)), overwhelming rate capability (200 mA h g(-1) at 29.7 A g(-1)) and excellent cycling stability (capacity retention of 99.8% after 200 cycles at 0.2 A g(-1)). Coupled by a Na3V2(PO4)(3) cathode and a Sb2O3@Sb anode, a full cell was further constructed and delivers excellent performance (reversible capacity, cycling stability and rate capability). Most importantly, the sodium storage mechanisms of the Sb2O3@Sb nanocomposite were unveiled by operando X-ray diffraction and Raman techniques.