Metal-organic framework on graphene derived hierarchical carbon supported tin dioxide nanocomposite for superior lithium ion storage

Tin dioxide (SnO₂) based anode material is investigated as an alternative choice to current graphite counterpart for lithium-ion batteries. Effective dispersing SnO₂ nanocrystals in a rationally designed carbon matrix with distinctive microstructures is critical for the enhancement of the electrochemical performances. Herein, 1,3,5-benzenetricarboxylic acid (C₉H₆O₆, H₃BTC) based 1D metal–organic framework (MOF) material Sn-BTC and tea polyphenol (TP) modified 2D reduced graphene oxide (RGO) samples are firstly prepared, which are further employed to engineer a Sn-BTC/TP-RGO precursor with unique microstructures in a mild hydrothermal condition. Finally, the Sn-BTC/TP-RGO can be directly converted the hierarchical SnO₂/C/RGO sample, in which SnO₂ nanocrystals are well dispersed by the 1D pyrolytic carbon and 2D RGO skeleton after a thermal treatment. Critical challenges of MOF degradation, inhomogeneous distribution of SnO₂ nanocrystals and over reassembly of the RGO layers are well addressed. The SnO₂/C/RGO nanocomposite shows superior lithium ion storage behaviors than the controlled samples in half-cell, which has a high specific capacity of 780.03 mAh·g⁻¹ over 200 cycles at a low-density current of 200 mA·g⁻¹, a stable capacity of about 698.27 mAh·g⁻¹ over 1000 cycles at a high-density current of 1000 mA·g⁻¹. Moreover, the full-cell performance and the lithium ion storage mechanism of the SnO₂/C/RGO sample are studied.