Porous hierarchical TiO_2/MoS_2/RGO nanoflowers as anode material for sodium ion batteries with high capacity and stability

摘要

To enhance the reversible capacity and cycle stability of MoS2 as anode materials for sodium ion batteries (SIBs), we constructed a hybrid architecture composed of MoS2 and TiO2 nanosheets, linking with reduced graphene oxide (RGO) to another TiO2/MoS2 to form a nanoflower structure. Owing to layered RGO coupled with TiO2/ MoS2 hybrid, such a composite offered interconnected conductive channels to short shuttle path of Na+ ions and favorable transport kinetics under charge/discharge cycling. Moreover, this unique structure showed a porous and hierarchical architecture, which not only buffered volume changes but also provided more electrochemical active sites during insertion/deintercalation processes of Na ions. Outstanding electrochemical performances were identified by the component matching effect among TiO2, MoS2 and RGO with a three-dimensional (3D) interconnected network, exhibiting a good reversible capacity of 616 mA h g(-1) after 100 cycles at 0.1 A g(-1), an excellent rate capability of 250 mA h g(-1) even at 5A g(-1) and a long cycling stability of 460 mA h g(-1) with a capacity fluctuation of 0.03% per cycle within 350 cycles at 1 A g(-1).