Assembly of mesoporous SnO2 spheres and carbon nanotubes network as a high-performance anode for lithium-ion batteries

We report a facile and effective aerosol-spray strategy toward high-performance anodes for lithium-ion batteries by incorporating mesoporous SnO2 spheres of high-capacity materials with surface-modified carbon nanotubes (MCNTs). SnO2 nanocrystals are self-assembled into mesoporous spheres, and MCNTs with abundant carboxylic groups serve as a conductive scaffold. Driven by the strong interaction between the surface of metal oxide and the carboxylic groups on CNTs, a robust nanocomposite architecture is in situ formed. Such nanocomposite architecture possesses several advantages as an anode for lithium-ion batteries. First, mesoporous SnO2 spheres inherit the advantageous features of conventional nanoparticles, such as the capability to accommodate volume expansion and reduce Li+ diffusion distance. Second, the robust interface between nanocrystals in the SnO2 spheres provides the high structural stability that would prolong the life span of the electrode. Third, MCNTs that strongly bind to SnO2 spheres serve as a three-dimensional network, offering both improved electronic transport and mechanical strength of the electrode. Therefore, as-prepared nanocomposite delivers high capacity of 963 mAh g−1 at 0.1 C and 701 mAh g−1 at 5 C, respectively. Significantly improved cycling performance is achieved over the bare SnO2 spheres counterpart.