MOF-derived hollow SiOx nanoparticles wrapped in 3D porous nitrogen-doped graphene aerogel and their superior performance as the anode for lithium-ion batteries.

A nanocomposite anode material consisting of metal-organic framework (MOF)-derived hollow SiOx nanoparticles wrapped in three dimensional (3D) nitrogen-doped graphene aerogel (N-GA) has been fabricated through a facile three-step approach, involving MOF-template inducting, self-assembly and nitrogen-doping, freeze-drying and thermal treatment process. The hollow SiOx nanoparticles with an average size of 100-160 nm are distributed on 3D N-GA. Such nanocomposites possess a 3D porous structure with a BET surface area as high as 426.3 m2 g-1. In this nanostructure, the N-GA's property of interconnected porous network enables it to provide pathways for rapid electron transfer and Li+ transport, while the MOF-derived hollow SiOx nanoparticles with void space can accommodate the volume change during a lithiation/delithiation process. As a result, high rate capability (675 mA h g-1 under 50 C) as well as long-life cycling stability (1233.2 mA h g-1 under 10 C, 86% capacity retention over 500 cycles) is achieved.