High Performance Sodium Ion Anodes Based on Sn4P3 Encapsulated within Amphiphilic Graphene Tubes

Abstract High‐performance sodium‐ion anode composites are synthesized through confined growth Sn 4 P 3 nanoparticles within amphiphilic graphene tubes, which provide mechanical robustness, the ability to confine Sn 4 P 3 particles with their highly conductive frameworks, and the capability to accommodate the volume change of the particles during cycling. This unique structure endows a sodium‐ion anode with high reversible capacity (821 mA h g −1 ), excellent rate capability (326 mA h g −1 at 20 A g −1 ), and cycling stability (>90% reversible capacity retention after 500 cycles). This strategy can be extended to other conversion‐ and alloying‐type materials that experience dramatic volume change during charging and discharging.