A Sandwich‐Like Hierarchically Porous Carbon/Graphene Composite as a High‐Performance Anode Material for Sodium‐Ion Batteries

A sandwich-like hierarchically porous carbon/graphene (G@HPC) composite is synthesized using a facile ionothermal process. The composite exhibits high specific capacity, remarkable cycling stability, and high-rate capability because of the synergistic effect of low-graphitized porous carbon with hierarchical structure and highly conductive graphene sandwiched between porous carbons.