Facilely synthesis of SnO₂ dots decorated reduced graphene oxide with ultra-long lithium storage life

In lithium-ion batteries (LIBs), commercial anodic graphite has reached its limit of theoretical capacity and some metal-based materials are drawing substantial attention due to their higher Li⁺ storage ability and better cyclic performance. In this paper, SnO₂ dots are facilely bridged chemically with reduced graphene oxide (rGO) nanosheets via a modified colloidal coagulation synthesis and a following calculation process in air. As anodes for LIBs, the obtained rGO/SnO₂ shows excellent electrochemical performances. At 1 and 2 A·g⁻¹, the rGO/SnO₂-70 electrode delivers stable reversible capacities of 584 and 378 mAh·g⁻¹ after 1000 cycles, respectively. It is believed that SnO₂ dots shorten the Li⁺ transport path length and support more electroactive sites for Li⁺ alloying/de-alloying reactions, leading to high reversible capacities. Meanwhile, the bridged chemically SnO₂ dots could prevent the re-stacking of rGO nanosheets. On the other hand, the conductive underneath core-rGO enables an ultrafast electron transport and accommodates the volume changes of the SnO₂ dots, leading to a good cyclic stability. This study provides a reference for the novel anodic carbonaceous materials with high capacity at high current density and ultra-long cyclic life.