The preparation of flexible graphene sponges embedded Sn nanospheres through Sn-C bonding and their improved electrochemical performances

A chemical reduction route was designed to prepare flexible and free standing 3D-rGO porous sponges embedded Sn nanospheres (3D-rGO/Sn). It is revealed the relation between phase composition and contact and charge-transfer resistances. The structural and interfacial stabilization of 3D-rGO/Sn through Sn-C chemical bonds can effectively preserve the isolated Sn nanospheres   from detaching, and enhance the charge transfer. Simultaneously, Sn nanosphere wrapped by thin graphene layers could alleviate the large stress generated from the volume expansion of Sn. Finally, for lithium-ion batteries,   the optimal 3D-rGO/Sn anode exhibited an excellent cycling stability performance and rate performance compared to Sn nanospheres and the mixture of 3D-rGO and Sn.