Sn Nanoparticles Encapsulated in 3D Nanoporous Carbon Derived from a Metal-Organic Framework for Anode Material in Lithium-Ion Batteries

Three-dimensional nanoporous carbon frameworks encapsulated Sn nanoparticles (Sn@3D-NPC) are developed by a facile method as an improved lithium ion battery anode. The Sn@3D-NPC delivers a reversible capacity of 740 mAh g^-1 after 200 cycles at a current density of 200 mA g^-1, corresponding to a capacity retention of 85% (against the second capacity) and high rate capability (300 mAh g^-1 at 5 A g^-1). Compared to the Sn nanoparticles (SnNPs), such improvements are attributed to the 3D porous and conductive framework. The whole structure can provide not only the high electrical conductivity that facilities the electron transfer but also the elasticity that will suppress the volume expansion and aggregation of SnNPs during the charge and discharge process. This work opens a new application of metal-organic frameworks in energy storage.