Facile synthesis of ultrathin-shell graphene hollow spheres for high-performance lithium-ion batteries

In this work, ultrathin-shell graphene hollow spheres have been designed and synthesized from the graphene oxide nanosheets by a simple template assisted method without surfactant. It is found that the obtained graphene hollow spheres have a high surface area (248.3 m(2) g(-1)), ultrathin porous shells (5 nm) and an interconnected structure. More strikingly, the as-prepared graphene hollow spheres exhibit outstanding electrochemical performance as an anode material for lithium-ion batteries. Even at a high current density of 5000 mAg(-1), a high reversible specific capacity of 249.3 mAh g(-1) can be achieved. Furthermore, after 100 cycles, about 97.1% of the specific capacity is maintained at a high current density of 1000 mAg(-1). The excellent electrochemical properties could be attributed to the attractive structure advantages of the graphene hollow spheres including the high surface area, ultrathin porous shells and an interconnected structure. (C) 2014 Elsevier Ltd. All rights reserved.