Synthesis of SnO2/Sn hybrid hollow spheres as high performance anode materials for lithium ion battery

Abstract The hollow SnO 2 spheres were synthesized by using carbon spheres as hard templates, and then carbon-coated SnO 2 /Sn hybrid hollow spheres can be obtained through annealing process after carbon coating. The as-prepared hybrid spheres are well dispersed and coated with a uniform carbon layer. The carbon-coated SnO 2 /Sn hybrid hollow spheres electrode exhibits high initial Coulombic efficiency (82.3%), high reversible capacity and good cycling stability (the initial charge and discharge capacity of 878.7 and 1061.6 mA h/g was achieved and the discharge capacities maintained 401 mA h/g after 50 cycles at 0.1 C) and good rate performance (1156.8 mA h/g at 0.1 C, 752.2 mA h/g at 0.2 C, 481.4 mA h/g at 0.5 C, 289.5 mA h/g at 1 C, and 120.6 mA h/g at 2 C, and more importantly, when the current density finally backs to 0.1 C, a capacity of 811.6 mA h/g can be restored) for anode materials in lithium ion batteries due to the hierarchical porous structure, carbon coating and the presence of Sn.