The composite of carbon nanotube connecting SnO2/reduced graphene clusters as highly reversible anode material for lithium-/sodium-ion batteries and full cell

Abstract To form hierarchical anode materials for fast lithium-/sodium storage, nanocrystallites SnO 2 (5 nm) on reduced graphene nanosheets (rGO) are successfully synthesized through ultrasonication and cryodesiccation, the as-produced SnO 2 /rGO clusters are homogeneously connected by carbon nanotube (CNT) through cryodesiccation. rGO with high specific surface area efficiently buffers the volumetric change and the pulverization of SnO 2 during lithiation/delithiation process. CNTs not only hinder the restack of SnO 2 /rGO clusters but also as conductive bridges connect the scattered SnO 2 /rGO clusters, which consequently improve the cycle stability and rate performance of samples. At the current density of 0.1 A g −1 , SnO 2 /rGO/CNT sample presents the initial discharge and charge capacities of 1678.6 and 1091.2 mAh g −1 . At 5 A g −1 , SnO 2 /rGO/CNT sample delivers 434.7 mAh g −1 that is higher than SnO 2 /rGO sample with 251.7 mAh g −1 . Moreover, the SnO 2 /rGO/CNT - LiCoO 2 full cell shows high capacity of 852.6 mAh g −1 at 0.1 A g −1 with a CE of 99.4%. The result indicates that CNTs can effectively achieve the integrity of the material by connecting other clusters of metal oxides and rGO.