Assembly of Tin Oxide/Graphene Nanosheets into 3D Hierarchical Frameworks for High‐Performance Lithium Storage

3D hierarchical tin oxide/graphene frameworks (SnO 2 /GFs) were built up by the in situ synthesis of 2D SnO 2 /graphene nanosheets followed by hydrothermal assembly. These SnO 2 /GFs exhibited a 3D hierarchical porous architecture with mesopores (≈3 nm), macropores (3–6 μm), and a large surface area (244 m 2  g −1 ), which not only effectively prevented the agglomeration of SnO 2 nanoparticles, but also facilitated fast ion and electron transport in 3D pathways. As a consequence, the SnO 2 /GFs exhibited a high capacity of 830 mAh g −1 for up to 70 charge–discharge cycles at 100 mA g −1 . Even at a high current density of 500 mA g −1 , a reversible capacity of 621 mAh g −1 could be maintained for SnO 2 /GFs with excellent cycling stability. Such performance is superior to that of previously reported SnO 2 /graphene and other SnO 2 /carbon composites with similar weight contents of SnO 2 .