Hierarchical TiO2/C micro–nano spheres as high-performance anode materials for sodium ion batteries

Abstract

The hierarchical TiO2/C microspheres were obtained via a facile method of in-situ hydrolysis and spray drying. Antase TiO2 nanoparticles were coherent to microspheres TiO2/C due to the pyrolysis of carbon source (PVP). Besides, the favorable electron transfer from carbon to TiO2 improves the electronic conductivity of TiO2 via the presence of Ti–C bond within TiO2/C composite. Charge-discharge tests show that TiO2/C microspheres delivered a good rate capability of 106.1[Formula: see text]mAh[Formula: see text]g[Formula: see text] at the high current density of 5[Formula: see text]A[Formula: see text]g[Formula: see text] and an enhanced cyclic capacity. The superior electrochemical performance could be ascribed to the porous micro–nano structure, smaller crystal size and increased conductivity. The synthesis of TiO2/C microspheres is easy to scale up for satisfying high-performance sodium storage.