Graphene-based carbon coated tin oxide as a lithium ion battery anode material with high performance

In this study, we synthesized an excellent ternary graphene-based carbon coated SnO₂ (rGO/PC/SnO₂) nanocomposite anode for lithium ion batteries (LIBs), in which carbon-coated SnO₂ nanoparticles homogeneously grow on the surface of reduced graphene oxide (rGO) using glucose as the soft templating agent. Using glucose can limit the growth of the SnO₂ particles; as a result, the size of the SnO₂ particles would be relatively uniform. Moreover, the carbon coated on the surface of SnO₂ particles can effectively prevent their agglomeration on the surface of rGO and limit their volume expansion during charge-discharge cycles. The porous structure of the rGO/PC/SnO₂ nanocomposite can effectively accommodate the severe volume variation upon cycling and provide additional contact areas between the active material and the electrolyte. Significantly, the rGO/PC/SnO₂ anode delivers an initial specific discharge capacity of 2238.2 mA h g^-1 and retains 1467.8 mA h g^-1 after 150 cycles at a current density of 0.1C (1C = 782 mA g^-1). Even at the high specific current of 1C after 200 cycles, the reversible specific capacity is still as high as 618.3 mA h g^-1. The rGO/PC/SnO₂ anode exhibits excellent rate performances and possesses a reversible specific capacity of 445.9 mA h g^-1 at 5C implying its good structural stability.